diff --git a/src/js/angular/models/ttyg/agent-form.js b/src/js/angular/models/ttyg/agent-form.js
index 18f01dbe8..efa2c1ddd 100644
--- a/src/js/angular/models/ttyg/agent-form.js
+++ b/src/js/angular/models/ttyg/agent-form.js
@@ -260,6 +260,10 @@ export class ExtractionMethodsFormModel {
     getRetrievalExtractionMethod() {
         return this.getExtractionMethod(ExtractionMethod.RETRIEVAL);
     }
+
+    getFTSSearchExtractionMethod() {
+        return this.getExtractionMethod(ExtractionMethod.FTS_SEARCH);
+    }
 }
 
 export class ExtractionMethodFormModel {
diff --git a/src/js/angular/ttyg/controllers/agent-settings-modal.controller.js b/src/js/angular/ttyg/controllers/agent-settings-modal.controller.js
index 98915e3f5..99471ab67 100644
--- a/src/js/angular/ttyg/controllers/agent-settings-modal.controller.js
+++ b/src/js/angular/ttyg/controllers/agent-settings-modal.controller.js
@@ -241,6 +241,9 @@ function AgentSettingsModalController(
      */
     $scope.updateSimilaritySearchPanel = (clearIndexSelection = false) => {
         const similaritySearchExtractionMethod = $scope.agentFormModel.assistantExtractionMethods.getSimilarityExtractionMethod();
+        if (!similaritySearchExtractionMethod.selected) {
+            return;
+        }
         if (clearIndexSelection) {
             similaritySearchExtractionMethod.similarityIndex = null;
         }
@@ -254,6 +257,9 @@ function AgentSettingsModalController(
      */
     $scope.updateRetrievalConnectorPanel = (clearSelection = false) => {
         const retrievalExtractionExtractionMethod = $scope.agentFormModel.assistantExtractionMethods.getRetrievalExtractionMethod();
+        if (!retrievalExtractionExtractionMethod.selected) {
+            return;
+        }
         if (clearSelection) {
             retrievalExtractionExtractionMethod.retrievalConnectorInstance = null;
         }
@@ -262,8 +268,19 @@ function AgentSettingsModalController(
 
     $scope.checkIfFTSEnabled = () => {
         if (!$scope.agentFormModel.repositoryId) {
+            $scope.agentSettingsForm.$setValidity('FTSDisabled', false);
             return;
         }
+
+        const ftsSearchExtractionMethod = $scope.agentFormModel.assistantExtractionMethods.getFTSSearchExtractionMethod();
+        if (!ftsSearchExtractionMethod.selected) {
+            // clear the validation status if method is deselected.
+            $scope.agentSettingsForm.$setValidity('FTSDisabled', true);
+            return;
+        }
+
+        $scope.extractionMethodLoaderFlags[ExtractionMethod.FTS_SEARCH] = true;
+
         // pass a fake repository info object with only an id because we don't care for the location
         RepositoriesRestService.getRepositoryModel({id: $scope.agentFormModel.repositoryId}).then((repositoryModel) => {
             $scope.ftsEnabled = repositoryModel.getParamValue(REPOSITORY_PARAMS.enableFtsIndex);
@@ -273,6 +290,7 @@ function AgentSettingsModalController(
         })
         .finally(() => {
             $scope.extractionMethodLoaderFlags[ExtractionMethod.FTS_SEARCH] = false;
+            $scope.agentSettingsForm.$setValidity('FTSDisabled', $scope.ftsEnabled);
         });
     };
 
@@ -282,9 +300,7 @@ function AgentSettingsModalController(
      * able to validate if the FTS is enabled for that selected repository.
      */
     $scope.onRepositoryChange = () => {
-        $scope.checkIfFTSEnabled();
-        $scope.updateSimilaritySearchPanel(true);
-        $scope.updateRetrievalConnectorPanel(true);
+        refreshValidations(true, true);
     };
 
     /**
@@ -442,7 +458,6 @@ function AgentSettingsModalController(
     };
 
     const handleFTSExtractionMethodPanelToggle = (extractionMethod) => {
-        $scope.extractionMethodLoaderFlags[extractionMethod.method] = true;
         $scope.checkIfFTSEnabled();
     };
 
@@ -556,6 +571,32 @@ function AgentSettingsModalController(
         [ExtractionMethod.RETRIEVAL]: (extractionMethod) => handleRetrievalConnectorExtractionMethodPanelToggle(extractionMethod)
     };
 
+    const refreshValidations = (clearIndexSelection = false, clearRetrievalConnectorSelection = false) => {
+        $scope.checkIfFTSEnabled();
+        $scope.updateSimilaritySearchPanel(clearIndexSelection);
+        $scope.updateRetrievalConnectorPanel(clearRetrievalConnectorSelection);
+    };
+
+    const onTabVisibilityChanged = () => {
+        if (!document.hidden) {
+            refreshValidations();
+        }
+    };
+
+    // =========================
+    // Subscriptions
+    // =========================
+
+    const removeAllSubscribers = () => {
+        document.removeEventListener("visibilitychange", onTabVisibilityChanged);
+    };
+
+    document.addEventListener("visibilitychange", onTabVisibilityChanged);
+
+    // Deregister the watcher when the scope/directive is destroyed
+    $scope.$on('$destroy', removeAllSubscribers);
+
+
     // =========================
     // Initialization
     // =========================
diff --git a/src/js/angular/ttyg/templates/modal/agent-settings-modal.html b/src/js/angular/ttyg/templates/modal/agent-settings-modal.html
index 5a2f022f2..816fde378 100644
--- a/src/js/angular/ttyg/templates/modal/agent-settings-modal.html
+++ b/src/js/angular/ttyg/templates/modal/agent-settings-modal.html
@@ -134,6 +134,7 @@ <h4 class="modal-title">{{(
 
                         <div
                             ng-if="extractionMethod.expanded && extractionMethod.method === extractionMethods.FTS_SEARCH"
+                            ng-class="{'has-error': agentSettingsForm.$error.FTSDisabled}"
                             class="extraction-method-options">
                             <button class="btn btn-link btn-sm pull-right"
                                     ng-click="checkIfFTSEnabled()"
@@ -167,6 +168,7 @@ <h4 class="modal-title">{{(
 
                         <div
                             ng-if="extractionMethod.expanded && extractionMethod.method === extractionMethods.SIMILARITY"
+                            ng-class="{'has-error': agentSettingsForm.$error.missingIndex}"
                             class="extraction-method-options">
                             <button class="btn btn-link btn-sm pull-right"
                                     ng-click="updateSimilaritySearchPanel()"
diff --git a/test-cypress/integration/ttyg/create-agent.spec.js b/test-cypress/integration/ttyg/create-agent.spec.js
index f93ba4add..540ae68e4 100644
--- a/test-cypress/integration/ttyg/create-agent.spec.js
+++ b/test-cypress/integration/ttyg/create-agent.spec.js
@@ -517,14 +517,26 @@ describe('TTYG create new agent', () => {
         TtygAgentSettingsModalSteps.getSystemInstructionsWarning().should('not.exist');
     });
 
-    it('should reset validation error when similarity search/ChatGPT connector are disabled', () => {
+    it('should reset validation error when FTS, similarity search or ChatGPT connector are disabled', () => {
         // When I open agent settings dialog and make all steps so the create button became enabled.
         TTYGStubs.stubChatsListGetNoResults();
         TTYGStubs.stubAgentListGet('/ttyg/agent/get-agent-list-0.json');
+        SimilarityIndexStubs.stubGetSimilarityIndexes('/similarity/get-similarity-indexes-0.json');
         TTYGViewSteps.visit();
         cy.wait('@get-all-repositories');
         TTYGViewSteps.createFirstAgent();
+        TtygAgentSettingsModalSteps.enableSparqlExtractionMethod();
+        TtygAgentSettingsModalSteps.selectSparqlMethodOntologyGraph();
+        TtygAgentSettingsModalSteps.getSaveAgentButton().should('be.enabled');
+
+        // When enable FTS extraction method and selected repository has not fts search enabled.
         TtygAgentSettingsModalSteps.enableFtsExtractionMethod();
+        // Then I expect the create button be disabled.
+        TtygAgentSettingsModalSteps.getSaveAgentButton().should('be.disabled');
+
+        // When I disable FTS extraction method
+        TtygAgentSettingsModalSteps.disableFtsExtractionMethod();
+        // Then I expect the save button be enabled because is deselected
         TtygAgentSettingsModalSteps.getSaveAgentButton().should('be.enabled');
 
         // When enable the similarity index method