diff --git a/ui-ngx/src/app/modules/home/components/alarm-rules/cf-alarm-rule-condition.component.ts b/ui-ngx/src/app/modules/home/components/alarm-rules/cf-alarm-rule-condition.component.ts
index fe0670b4e7..ef539af6f5 100644
--- a/ui-ngx/src/app/modules/home/components/alarm-rules/cf-alarm-rule-condition.component.ts
+++ b/ui-ngx/src/app/modules/home/components/alarm-rules/cf-alarm-rule-condition.component.ts
@@ -142,10 +142,9 @@ export class CfAlarmRuleConditionComponent implements ControlValueAccessor, Vali
   }
 
   ngOnChanges(changes: SimpleChanges) {
-    if (changes.arguments) {
-      if (changes.arguments && !changes.arguments.firstChange) {
-        this.recalculateArgumentValidity();
-      }
+    if (changes.arguments && !changes.arguments.firstChange) {
+      this.recalculateArgumentValidity();
+      this.onValidatorChange();
     }
   }
 
diff --git a/ui-ngx/src/app/modules/home/components/alarm-rules/cf-alarm-rule.component.ts b/ui-ngx/src/app/modules/home/components/alarm-rules/cf-alarm-rule.component.ts
index 706477f72a..d9b7f868ac 100644
--- a/ui-ngx/src/app/modules/home/components/alarm-rules/cf-alarm-rule.component.ts
+++ b/ui-ngx/src/app/modules/home/components/alarm-rules/cf-alarm-rule.component.ts
@@ -84,6 +84,7 @@ export class CfAlarmRuleComponent implements ControlValueAccessor, OnInit, Valid
   });
 
   private propagateChange = (v: any) => { };
+  private onValidatorChange = () => { };
 
   constructor(private dialog: MatDialog,
               private fb: FormBuilder,
@@ -97,12 +98,21 @@ export class CfAlarmRuleComponent implements ControlValueAccessor, OnInit, Valid
   registerOnTouched(fn: any): void {
   }
 
+  registerOnValidatorChange(fn: () => void): void {
+    this.onValidatorChange = fn;
+  }
+
   ngOnInit() {
     this.alarmRuleFormGroup.valueChanges.pipe(
       takeUntilDestroyed(this.destroyRef)
     ).subscribe(() => {
       this.updateModel();
     });
+    this.alarmRuleFormGroup.statusChanges.pipe(
+      takeUntilDestroyed(this.destroyRef)
+    ).subscribe(() => {
+      this.onValidatorChange();
+    });
   }
 
   setDisabledState(isDisabled: boolean): void {
diff --git a/ui-ngx/src/app/modules/home/components/alarm-rules/create-cf-alarm-rules.component.ts b/ui-ngx/src/app/modules/home/components/alarm-rules/create-cf-alarm-rules.component.ts
index 4d9884f851..345e155ae1 100644
--- a/ui-ngx/src/app/modules/home/components/alarm-rules/create-cf-alarm-rules.component.ts
+++ b/ui-ngx/src/app/modules/home/components/alarm-rules/create-cf-alarm-rules.component.ts
@@ -77,12 +77,16 @@ export class CreateCfAlarmRulesComponent implements ControlValueAccessor, Valida
   private usedSeverities: AlarmSeverity[] = [];
 
   private propagateChange = (v: any) => { };
+  private onValidatorChange = () => { };
 
   constructor(private fb: FormBuilder,
               private destroyRef: DestroyRef) {
     this.createAlarmRulesFormGroup.valueChanges.pipe(
       takeUntilDestroyed(this.destroyRef)
     ).subscribe(() => this.updateModel());
+    this.createAlarmRulesFormGroup.statusChanges.pipe(
+      takeUntilDestroyed(this.destroyRef)
+    ).subscribe(() => this.onValidatorChange());
   }
 
   registerOnChange(fn: any): void {
@@ -92,6 +96,10 @@ export class CreateCfAlarmRulesComponent implements ControlValueAccessor, Valida
   registerOnTouched(fn: any): void {
   }
 
+  registerOnValidatorChange(fn: () => void): void {
+    this.onValidatorChange = fn;
+  }
+
   createAlarmRulesFormArray(): UntypedFormArray {
     return this.createAlarmRulesFormGroup.get('createAlarmRules') as UntypedFormArray;
   }
diff --git a/ui-ngx/src/app/modules/home/components/iot-hub/iot-hub-actions.service.ts b/ui-ngx/src/app/modules/home/components/iot-hub/iot-hub-actions.service.ts
index 62e44e467c..536c9da878 100644
--- a/ui-ngx/src/app/modules/home/components/iot-hub/iot-hub-actions.service.ts
+++ b/ui-ngx/src/app/modules/home/components/iot-hub/iot-hub-actions.service.ts
@@ -17,11 +17,9 @@
 import { Injectable } from '@angular/core';
 import { MatDialog } from '@angular/material/dialog';
 import { Observable, of } from 'rxjs';
-import { map, mergeMap } from 'rxjs/operators';
 import { MpItemVersionView } from '@shared/models/iot-hub/iot-hub-version.models';
 import { ItemType } from '@shared/models/iot-hub/iot-hub-item.models';
 import { DeviceInstalledItemDescriptor, IotHubInstalledItem } from '@shared/models/iot-hub/iot-hub-installed-item.models';
-import { IotHubApiService } from '@core/http/iot-hub-api.service';
 import { EntityId } from '@shared/models/id/entity-id';
 import { TbIotHubAddItemDialogComponent, IotHubAddItemDialogData, IotHubAddItemDialogResult } from './iot-hub-add-item-dialog.component';
 import { TbIotHubItemDetailDialogComponent, IotHubItemDetailDialogData, IotHubItemDetailDialogMode } from './iot-hub-item-detail-dialog.component';
@@ -35,8 +33,7 @@ import { TbIotHubInstalledItemsDialogComponent, IotHubInstalledItemsDialogData }
 export class IotHubActionsService {
 
   constructor(
-    private dialog: MatDialog,
-    private iotHubApiService: IotHubApiService
+    private dialog: MatDialog
   ) {}
 
   openItemDetail(item: MpItemVersionView, installedItem?: IotHubInstalledItem, installedItemsCount?: number,
@@ -109,13 +106,8 @@ export class IotHubActionsService {
       panelClass: ['tb-dialog'],
       disableClose: true,
       autoFocus: false,
-      data: { itemName: installedItem.itemName, itemType: installedItem.itemType }
-    }).afterClosed().pipe(
-      mergeMap((confirmed) =>
-        confirmed
-          ? this.iotHubApiService.deleteInstalledItem(installedItem.id.id).pipe(map(() => true))
-          : of(false) )
-    );
+      data: { installedItemId: installedItem.id.id, itemName: installedItem.itemName, itemType: installedItem.itemType }
+    }).afterClosed();
   }
 
   installDevice(item: MpItemVersionView): Observable<string> {
diff --git a/ui-ngx/src/app/modules/home/components/iot-hub/iot-hub-delete-dialog.component.ts b/ui-ngx/src/app/modules/home/components/iot-hub/iot-hub-delete-dialog.component.ts
index 4353f1a9f6..be91644741 100644
--- a/ui-ngx/src/app/modules/home/components/iot-hub/iot-hub-delete-dialog.component.ts
+++ b/ui-ngx/src/app/modules/home/components/iot-hub/iot-hub-delete-dialog.component.ts
@@ -20,8 +20,11 @@ import { Router } from '@angular/router';
 import { Store } from '@ngrx/store';
 import { AppState } from '@core/core.state';
 import { DialogComponent } from '@shared/components/dialog.component';
+import { IotHubInstalledItem } from 'src/app/shared/models/iot-hub/iot-hub-installed-item.models';
+import { IotHubApiService } from '@core/http/iot-hub-api.service';
 
 export interface IotHubDeleteDialogData {
+  installedItemId: string;
   itemName: string;
   itemType?: string;
 }
@@ -38,13 +41,18 @@ export class TbIotHubDeleteDialogComponent extends DialogComponent<TbIotHubDelet
     protected store: Store<AppState>,
     protected router: Router,
     protected dialogRef: MatDialogRef<TbIotHubDeleteDialogComponent, boolean>,
-    @Inject(MAT_DIALOG_DATA) public data: IotHubDeleteDialogData
+    @Inject(MAT_DIALOG_DATA) public data: IotHubDeleteDialogData,
+    private iotHubApiService: IotHubApiService
   ) {
     super(store, router, dialogRef);
   }
 
   confirm(): void {
-    this.dialogRef.close(true);
+    this.iotHubApiService.deleteInstalledItem(this.data.installedItemId).subscribe(
+      () => {
+        this.dialogRef.close(true);
+      }
+    );
   }
 
   cancel(): void {
diff --git a/ui-ngx/src/app/modules/home/components/iot-hub/iot-hub-installed-items-table.component.ts b/ui-ngx/src/app/modules/home/components/iot-hub/iot-hub-installed-items-table.component.ts
index 281d1d1e0e..4435c82736 100644
--- a/ui-ngx/src/app/modules/home/components/iot-hub/iot-hub-installed-items-table.component.ts
+++ b/ui-ngx/src/app/modules/home/components/iot-hub/iot-hub-installed-items-table.component.ts
@@ -156,12 +156,9 @@ export class TbIotHubInstalledItemsTableComponent implements OnInit, OnChanges,
   }
 
   deleteItem(item: IotHubInstalledItem): void {
-    this.isLoading = true;
     this.iotHubActions.deleteItem(item).subscribe(deleted => {
       if (deleted) {
         this.loadData();
-      } else {
-        this.isLoading = false;
       }
     });
   }
@@ -247,12 +244,9 @@ export class TbIotHubInstalledItemsTableComponent implements OnInit, OnChanges,
   }
 
   updateItem(item: IotHubInstalledItem, publishedInfo: ItemPublishedVersionInfo): void {
-    this.isLoading = true;
     this.iotHubActions.updateItem(item, publishedInfo.publishedVersion, publishedInfo.publishedVersionId).subscribe(result => {
       if (result === 'updated') {
         this.loadData();
-      } else {
-        this.isLoading = false;
       }
     });
   }
diff --git a/ui-ngx/src/app/shared/components/time-unit-input.component.ts b/ui-ngx/src/app/shared/components/time-unit-input.component.ts
index 93293698b3..79482f378f 100644
--- a/ui-ngx/src/app/shared/components/time-unit-input.component.ts
+++ b/ui-ngx/src/app/shared/components/time-unit-input.component.ts
@@ -206,15 +206,13 @@ export class TimeUnitInputComponent implements ControlValueAccessor, Validator,
   writeValue(sec: number) {
     if (sec !== this.modelValue) {
       if (isDefinedAndNotNull(sec) && isNumeric(sec) && Number(sec) !== 0) {
-        this.timeInputForm.patchValue(this.parseTime(sec), {emitEvent: true});
+        this.timeInputForm.patchValue(this.parseTime(sec), {emitEvent: false});
         this.modelValue = sec;
       } else {
-        this.timeInputForm.patchValue({
-          time: 0,
-          timeUnit: TimeUnit.SECONDS
-        }, {emitEvent: false});
+        this.timeInputForm.patchValue(this.secondsModel(0), {emitEvent: false});
         this.modelValue = 0;
       }
+      this.refreshTimeValidators();
     }
   }
 
@@ -242,6 +240,14 @@ export class TimeUnitInputComponent implements ControlValueAccessor, Validator,
         }
       }
     }
+    return this.secondsModel(value);
+  }
+
+  private secondsModel(time: number): TimeUnitInputModel {
+    return {
+      time,
+      timeUnit: TimeUnit.SECONDS
+    };
   }
 
   private createStepMultipleOfValidator(): ValidatorFn {