diff --git a/application/src/main/java/org/thingsboard/server/controller/RpcV2Controller.java b/application/src/main/java/org/thingsboard/server/controller/RpcV2Controller.java
index b7c617259f..ae9081c39a 100644
--- a/application/src/main/java/org/thingsboard/server/controller/RpcV2Controller.java
+++ b/application/src/main/java/org/thingsboard/server/controller/RpcV2Controller.java
@@ -69,27 +69,11 @@ public class RpcV2Controller extends AbstractRpcController {
     @PreAuthorize("hasAnyAuthority('TENANT_ADMIN', 'CUSTOMER_USER')")
     @RequestMapping(value = "/persistent/{rpcId}", method = RequestMethod.GET)
     @ResponseBody
-    public ResponseEntity<Rpc> getPersistedRpc(@PathVariable("rpcId") String strRpc) throws ThingsboardException {
+    public Rpc getPersistedRpc(@PathVariable("rpcId") String strRpc) throws ThingsboardException {
         checkParameter("RpcId", strRpc);
         try {
             RpcId rpcId = new RpcId(UUID.fromString(strRpc));
-            Rpc rpc = checkRpcId(rpcId, Operation.READ);
-            HttpStatus status;
-            switch (rpc.getStatus()) {
-                case FAILED:
-                    status = HttpStatus.BAD_GATEWAY;
-                    break;
-                case TIMEOUT:
-                    status = HttpStatus.GATEWAY_TIMEOUT;
-                    break;
-                case QUEUED:
-                case DELIVERED:
-                    status = HttpStatus.ACCEPTED;
-                    break;
-                default:
-                    status = HttpStatus.OK;
-            }
-            return new ResponseEntity<>(rpc, status);
+            return checkRpcId(rpcId, Operation.READ);
         } catch (Exception e) {
             throw handleException(e);
         }
diff --git a/ui-ngx/src/app/core/api/widget-subscription.ts b/ui-ngx/src/app/core/api/widget-subscription.ts
index d888f759a8..e34fccf9c8 100644
--- a/ui-ngx/src/app/core/api/widget-subscription.ts
+++ b/ui-ngx/src/app/core/api/widget-subscription.ts
@@ -35,7 +35,7 @@ import {
   LegendKeyData,
   widgetType
 } from '@app/shared/models/widget.models';
-import { HttpErrorResponse, HttpResponse } from '@angular/common/http';
+import { HttpErrorResponse } from '@angular/common/http';
 import {
   calculateIntervalStartEndTime,
   calculateTsOffset,
@@ -69,7 +69,7 @@ import {
 } from '@shared/models/query/query.models';
 import { filter, map, switchMap, takeUntil } from 'rxjs/operators';
 import { AlarmDataListener } from '@core/api/alarm-data.service';
-import { PersistentRpc } from '@shared/models/rpc.models';
+import { RpcStatus } from '@shared/models/rpc.models';
 
 const moment = moment_;
 
@@ -710,8 +710,17 @@ export class WidgetSubscription implements IWidgetSubscription {
               if (persistent && persistentPollingInterval > 0) {
                 return timer(persistentPollingInterval / 2, persistentPollingInterval).pipe(
                   switchMap(() => this.ctx.deviceService.getPersistedRpc(response.rpcId, true)),
-                  filter((persistentResponse: HttpResponse<PersistentRpc>) => persistentResponse.status !== 202),
-                  map(persistentResponse => persistentResponse.body.response),
+                  filter(persistentRespons =>
+                    persistentRespons.status !== RpcStatus.DELIVERED && persistentRespons.status !== RpcStatus.QUEUED),
+                  switchMap(persistentResponse => {
+                    if (persistentResponse.status === RpcStatus.TIMEOUT) {
+                      return throwError({status: 504});
+                    } else if (persistentResponse.status === RpcStatus.FAILED) {
+                      return throwError({status: 502, statusText: persistentResponse.response.error});
+                    } else {
+                      return of(persistentResponse.response);
+                    }
+                  }),
                   takeUntil(rpcSubject)
                 );
               }
diff --git a/ui-ngx/src/app/core/http/device.service.ts b/ui-ngx/src/app/core/http/device.service.ts
index 77ee67f8c8..c881e038e9 100644
--- a/ui-ngx/src/app/core/http/device.service.ts
+++ b/ui-ngx/src/app/core/http/device.service.ts
@@ -17,7 +17,7 @@
 import { Injectable } from '@angular/core';
 import { defaultHttpOptionsFromConfig, RequestConfig } from './http-utils';
 import { Observable, ReplaySubject } from 'rxjs';
-import { HttpClient, HttpResponse } from '@angular/common/http';
+import { HttpClient } from '@angular/common/http';
 import { PageLink } from '@shared/models/page/page-link';
 import { PageData } from '@shared/models/page/page-data';
 import {
@@ -138,12 +138,8 @@ export class DeviceService {
     return this.http.post<Device>(`/api/rpc/twoway/${deviceId}`, requestBody, defaultHttpOptionsFromConfig(config));
   }
 
-  public getPersistedRpc(rpcId: string, fullResponse = false,
-                         config?: RequestConfig): Observable<PersistentRpc | HttpResponse<PersistentRpc>> {
-    return this.http.get<PersistentRpc>(`/api/rpc/persistent/${rpcId}`, {
-      ...defaultHttpOptionsFromConfig(config),
-      observe: fullResponse ? 'response' : undefined
-    });
+  public getPersistedRpc(rpcId: string, fullResponse = false, config?: RequestConfig): Observable<PersistentRpc> {
+    return this.http.get<PersistentRpc>(`/api/rpc/persistent/${rpcId}`, defaultHttpOptionsFromConfig(config));
   }
 
   public findByQuery(query: DeviceSearchQuery,