Do not strand edge sync when an event fetcher fails

application/src/main/java/org/thingsboard/server/service/edge/rpc/session/EdgeGrpcSession.java

@@ -366,7 +366,12 @@ public class EdgeGrpcSession implements EdgeSession {
 
                 @Override
                 public void onFailure(Throwable t) {
-                    log.error("[{}][{}] Exception during sync process", getTenantId(), getEdgeId(), t);
+                    log.error("[{}][{}] Exception during sync process, skipping fetcher {} and continuing",
+                            getTenantId(), getEdgeId(), next.getClass().getSimpleName(), t);
+                    // Keep walking the cursor: returning here leaves syncInProgress set for the life of the
+                    // session, so the edge never receives SyncCompletedMsg and both general downlink delivery
+                    // and uplink processing stay gated until the session is re-established.
+                    doSync(cursor);
                 }
             }, ctx.getGrpcCallbackExecutorService());
         } else {