diff --git a/asset/js/widget/Completer.js b/asset/js/widget/Completer.js
index a11548a3..1596d331 100644
--- a/asset/js/widget/Completer.js
+++ b/asset/js/widget/Completer.js
@@ -6,6 +6,7 @@ define(["../notjQuery"], function ($) {
         constructor(input, instrumented = false) {
             this.input = input;
             this.instrumented = instrumented;
+            this.hasBeenManuallyChanged = false; // Flag to identify if the input has been manually changed.
             this.selectionStartInput = null;
             this.selectionActive = false;
             this.mouseSelectionActive = false;
@@ -268,6 +269,8 @@ define(["../notjQuery"], function ($) {
 
         complete(input, value, data) {
             $(input).focus({ scripted: true });
+            // Disable autosubmit for the input in non-instrumented mode if the input is completed.
+            this.hasBeenManuallyChanged = false;
 
             if (this.instrumented) {
                 if (! Object.keys(data).length) {
@@ -321,8 +324,12 @@ define(["../notjQuery"], function ($) {
 
             if (! stopAtEdge && this.completedValue !== null) {
                 if (input === this.completedInput) {
+                    // Re-enable autosubmit for the input in non-instrumented mode when the user moves from suggestions back to the input.
+                    this.hasBeenManuallyChanged = true;
                     this.suggest(this.completedInput, this.completedValue);
                 } else {
+                    // Disable the autosubmit for the input in non-instrumented mode while moving through suggestions.
+                    this.hasBeenManuallyChanged = false;
                     this.suggest(this.completedInput, input.value, { ...input.dataset });
                 }
             }
@@ -476,6 +483,23 @@ define(["../notjQuery"], function ($) {
         }
 
         onFocusOut(event) {
+            if (! this.instrumented && this.shouldAutoSubmit()) {
+                setTimeout(() => {
+                    // Autosubmit if the user leaves the input and the input has been manually changed.
+                    // Only for non-instrumented mode — instrumented inputs (e.g. TermInput) handle
+                    // autosubmit themselves via BaseInput.autoSubmit() with proper term data.
+                    if (
+                        this.hasBeenManuallyChanged
+                        && ! this.hasSuggestions()
+                    ) {
+                        // Reset this flag since the user has navigated away from the input and the submit event
+                        // will be triggered by the input's form submit event handler.
+                        this.hasBeenManuallyChanged = false;
+                        $(this.input.form).trigger('submit', {submittedBy: this.input});
+                    }
+                }, 300);
+            }
+
             if (this.completedInput === null) {
                 // If there are multiple instances of Completer bound to the same suggestion container
                 // all of them try to handle the event. Though, only one of them is responsible and
@@ -495,6 +519,9 @@ define(["../notjQuery"], function ($) {
                     if (input !== completedInput) {
                         // Restore input if a suggestion lost focus
                         this.suggest(completedInput, this.completedValue);
+                        // This triggers the autosubmit if the user navigates away from the input for non-instrumented mode.
+                        // as the input is reset to the manually changed value once suggestions are hidden.
+                        this.hasBeenManuallyChanged = true;
                     }
 
                     this.hideSuggestions();
@@ -569,6 +596,8 @@ define(["../notjQuery"], function ($) {
                     $(this.completedInput).focus({ scripted: true });
                     this.suggest(this.completedInput, this.completedValue);
                     this.clearSelection();
+                    this.hasBeenManuallyChanged = true;
+
                     break;
                 case 'Tab':
                     event.preventDefault();
@@ -631,6 +660,15 @@ define(["../notjQuery"], function ($) {
 
         onKeyDown(event) {
             let suggestions;
+            const keys = ['Tab', 'ArrowDown', 'ArrowUp'];
+            if (
+                ! this.instrumented
+                && keys.includes(event.key)
+                && this.hasSuggestions()
+            ) {
+                // Disable the autosubmit if the user navigates away from the input but is within the suggestions.
+                this.hasBeenManuallyChanged = false;
+            }
 
             switch (event.key) {
                 case ' ':
@@ -676,7 +714,7 @@ define(["../notjQuery"], function ($) {
                     break;
                 case 'Escape':
                     if (this.hasSuggestions()) {
-                        this.hideSuggestions()
+                        this.hideSuggestions();
                         event.preventDefault();
                     }
 
@@ -712,7 +750,6 @@ define(["../notjQuery"], function ($) {
 
         onInput(event) {
             let input = event.target;
-
             if (input.minLength > 0 && input.value.length < input.minLength) {
                 return;
             }
@@ -730,6 +767,9 @@ define(["../notjQuery"], function ($) {
                 dataElement.value = input.value;
             }
 
+            // This flag triggers the autosubmit if the user navigates away from the input for non-instrumented mode
+            // and the input has the manually changed value.
+            this.hasBeenManuallyChanged = true;
             let [value, data] = this.prepareCompletionData(input);
             this.completedInput = input;
             this.completedValue = value;