diff --git a/ui-ngx/src/app/modules/home/components/widget/lib/gateway/abstract/gateway-connector-version-processor.abstract.ts b/ui-ngx/src/app/modules/home/components/widget/lib/gateway/abstract/gateway-connector-version-processor.abstract.ts
index 1a1c4f05bc..31b8ba8cf8 100644
--- a/ui-ngx/src/app/modules/home/components/widget/lib/gateway/abstract/gateway-connector-version-processor.abstract.ts
+++ b/ui-ngx/src/app/modules/home/components/widget/lib/gateway/abstract/gateway-connector-version-processor.abstract.ts
@@ -11,9 +11,9 @@ export abstract class GatewayConnectorVersionProcessor<BasicConfig> {
 
   getProcessedByVersion(): BasicConfig {
     if (this.isVersionUpdateNeeded()) {
-      return this.configVersion > this.gatewayVersion
-        ? this.getDowngradedVersion()
-        : this.getUpgradedVersion();
+      return this.configVersion < this.gatewayVersion
+        ? this.getUpgradedVersion()
+        : this.getDowngradedVersion();
     }
 
     return this.connector.configurationJson as unknown as BasicConfig;
diff --git a/ui-ngx/src/app/modules/home/components/widget/lib/gateway/abstract/mqtt-version-processor.abstract.ts b/ui-ngx/src/app/modules/home/components/widget/lib/gateway/abstract/mqtt-version-processor.abstract.ts
index 2a7bea0e1b..875b238d7e 100644
--- a/ui-ngx/src/app/modules/home/components/widget/lib/gateway/abstract/mqtt-version-processor.abstract.ts
+++ b/ui-ngx/src/app/modules/home/components/widget/lib/gateway/abstract/mqtt-version-processor.abstract.ts
@@ -1,15 +1,14 @@
-import {
-  GatewayConnectorVersionProcessor
-} from '@home/components/widget/lib/gateway/abstract/gateway-connector-version-processor.abstract';
+import { isEqual } from '@core/utils';
 import {
   GatewayConnector,
-  MQTTBasicConfig, MQTTBasicConfig_v3_5_2,
+  MQTTBasicConfig,
+  MQTTBasicConfig_v3_5_2,
   MQTTLegacyBasicConfig,
   RequestMappingData,
   RequestType,
-} from '@home/components/widget/lib/gateway/gateway-widget.models';
-import { isEqual } from '@core/utils';
-import { MqttVersionMappingUtil } from '@home/components/widget/lib/gateway/utils/mqtt-version-mapping.util';
+} from '../gateway-widget.models';
+import { MqttVersionMappingUtil } from '../utils/mqtt-version-mapping.util';
+import { GatewayConnectorVersionProcessor } from './gateway-connector-version-processor.abstract';
 
 export class MqttVersionProcessor extends GatewayConnectorVersionProcessor<MQTTBasicConfig> {
   private readonly mqttRequestTypeKeys = Object.values(RequestType);
@@ -20,7 +19,7 @@ export class MqttVersionProcessor extends GatewayConnectorVersionProcessor<MQTTB
   ) {
     super(gatewayVersionStr, connector);
   }
-  getUpgradedVersion(): MQTTBasicConfig {
+  getUpgradedVersion(): MQTTBasicConfig_v3_5_2 {
     const {
       connectRequests,
       disconnectRequests,
@@ -41,13 +40,13 @@ export class MqttVersionProcessor extends GatewayConnectorVersionProcessor<MQTTB
     };
 
     this.mqttRequestTypeKeys.forEach((key: RequestType) => {
-      const { [key]: removedKey, ...rest } = configurationJson as MQTTLegacyBasicConfig;
+      const { [key]: removedValue, ...rest } = configurationJson as MQTTLegacyBasicConfig;
       configurationJson = { ...rest } as any;
     });
 
     this.cleanUpConfigJson(configurationJson as MQTTBasicConfig_v3_5_2);
 
-    return configurationJson as MQTTBasicConfig;
+    return configurationJson as MQTTBasicConfig_v3_5_2;
   }
 
   getDowngradedVersion(): MQTTLegacyBasicConfig {
diff --git a/ui-ngx/src/app/modules/home/components/widget/lib/gateway/connectors-configuration/mqtt/basic-config/mqtt-basic-config.abstract.ts b/ui-ngx/src/app/modules/home/components/widget/lib/gateway/connectors-configuration/mqtt/basic-config/mqtt-basic-config.abstract.ts
index 072d8ba834..0394604d42 100644
--- a/ui-ngx/src/app/modules/home/components/widget/lib/gateway/connectors-configuration/mqtt/basic-config/mqtt-basic-config.abstract.ts
+++ b/ui-ngx/src/app/modules/home/components/widget/lib/gateway/connectors-configuration/mqtt/basic-config/mqtt-basic-config.abstract.ts
@@ -32,7 +32,9 @@ export abstract class AbstractMqttBasicConfigComponent<BasicConfig> implements C
 
   basicFormGroup: FormGroup;
   mappingTypes = MappingType;
+
   private destroy$ = new Subject<void>();
+
   private onChange: (value: BasicConfig) => void;
   private onTouched: () => void;
 
diff --git a/ui-ngx/src/app/modules/home/components/widget/lib/gateway/connectors-configuration/mqtt/basic-config/mqtt-basic-config.component.ts b/ui-ngx/src/app/modules/home/components/widget/lib/gateway/connectors-configuration/mqtt/basic-config/mqtt-basic-config.component.ts
index e2c9918179..541866dab8 100644
--- a/ui-ngx/src/app/modules/home/components/widget/lib/gateway/connectors-configuration/mqtt/basic-config/mqtt-basic-config.component.ts
+++ b/ui-ngx/src/app/modules/home/components/widget/lib/gateway/connectors-configuration/mqtt/basic-config/mqtt-basic-config.component.ts
@@ -80,8 +80,8 @@ export class MqttBasicConfigComponent extends AbstractMqttBasicConfigComponent<M
         maxNumberOfWorkers: broker.maxNumberOfWorkers,
         maxMessageNumberPerWorker: broker.maxMessageNumberPerWorker,
       } : {},
-      mapping: mapping || [],
-      broker: broker || {},
+      mapping: mapping ?? [],
+      broker: broker ?? {},
       requestsMapping: this.getRequestDataArray(requestsMapping as Record<RequestType, RequestMappingData[]>),
     };
 
diff --git a/ui-ngx/src/app/modules/home/components/widget/lib/gateway/gateway-connectors.component.ts b/ui-ngx/src/app/modules/home/components/widget/lib/gateway/gateway-connectors.component.ts
index 96e15a110f..b6e2dfc093 100644
--- a/ui-ngx/src/app/modules/home/components/widget/lib/gateway/gateway-connectors.component.ts
+++ b/ui-ngx/src/app/modules/home/components/widget/lib/gateway/gateway-connectors.component.ts
@@ -243,10 +243,6 @@ export class GatewayConnectorComponent extends PageComponent implements AfterVie
       delete value.class;
     }
 
-    if (this.gatewayVersion && !value.configVersion) {
-      value.configVersion = this.gatewayVersion;
-    }
-
     value.ts = Date.now();
 
     return value;
@@ -482,7 +478,7 @@ export class GatewayConnectorComponent extends PageComponent implements AfterVie
           value.configurationJson = {} as ConnectorBaseConfig;
         }
         value.basicConfig = value.configurationJson;
-        this.updateConnector({...value, configVersion: this.gatewayVersion ?? ''});
+        this.updateConnector(value);
         this.generate('basicConfig.broker.clientId');
         setTimeout(() => this.saveConnector());
     });
diff --git a/ui-ngx/src/app/modules/home/components/widget/lib/gateway/utils/mqtt-version-mapping.util.ts b/ui-ngx/src/app/modules/home/components/widget/lib/gateway/utils/mqtt-version-mapping.util.ts
index ffd517c3e9..23cc03dc4e 100644
--- a/ui-ngx/src/app/modules/home/components/widget/lib/gateway/utils/mqtt-version-mapping.util.ts
+++ b/ui-ngx/src/app/modules/home/components/widget/lib/gateway/utils/mqtt-version-mapping.util.ts
@@ -40,7 +40,7 @@ export class MqttVersionMappingUtil {
     ['attributeNameExpressionSource', 'responseTopicQoS', 'extensionConfig'];
 
   static mapMappingToUpgradedVersion(
-    mapping: LegacyConverterConnectorMapping[] | ConverterConnectorMapping[]
+    mapping: LegacyConverterConnectorMapping[]
   ): ConverterConnectorMapping[] {
     return mapping?.map(({ converter, topicFilter, subscriptionQos = 1 }) => {
       const deviceInfo = converter.deviceInfo ?? this.extractConverterDeviceInfo(converter);
@@ -54,12 +54,12 @@ export class MqttVersionMappingUtil {
       this.cleanUpOldFields(newConverter);
 
       return { converter: newConverter, topicFilter, subscriptionQos };
-    });
+    }) as ConverterConnectorMapping[];
   }
 
   static mapRequestsToUpgradedVersion(
     requestMapping: Record<RequestType,
-      RequestMappingData[] | LegacyRequestMappingData[]>
+      LegacyRequestMappingData[]>
   ): Record<RequestType, RequestMappingData[]> {
     return this.mqttRequestTypeKeys.reduce((acc, key: RequestType) => {
       if (!requestMapping[key]) {