diff --git a/frontend/src/components/modals/settings/AutocompleteCombobox.test.tsx b/frontend/src/components/modals/settings/AutocompleteCombobox.test.tsx
index 108ac25871..43385a148d 100644
--- a/frontend/src/components/modals/settings/AutocompleteCombobox.test.tsx
+++ b/frontend/src/components/modals/settings/AutocompleteCombobox.test.tsx
@@ -64,5 +64,21 @@ describe("AutocompleteCombobox", () => {
     expect(onChangeMock).toHaveBeenCalledWith("model2");
   });
 
+  it("should set the input value to the default key if the default key is not in the list", () => {
+    render(
+      <AutocompleteCombobox
+        ariaLabel="model"
+        items={[{ value: "m1", label: "model1" }]}
+        defaultKey="m2"
+        tooltip="tooltip"
+        onChange={onChangeMock}
+      />,
+    );
+
+    const modelInput = screen.getByRole("combobox", { name: "model" });
+
+    expect(modelInput).toHaveValue("m2");
+  });
+
   it.todo("should show a tooltip after 0.5 seconds of focus");
 });
diff --git a/frontend/src/components/modals/settings/AutocompleteCombobox.tsx b/frontend/src/components/modals/settings/AutocompleteCombobox.tsx
index c4cdc7af17..01d5891b30 100644
--- a/frontend/src/components/modals/settings/AutocompleteCombobox.tsx
+++ b/frontend/src/components/modals/settings/AutocompleteCombobox.tsx
@@ -1,7 +1,7 @@
-import { I18nKey } from "#/i18n/declaration";
 import { Autocomplete, AutocompleteItem, Tooltip } from "@nextui-org/react";
 import React from "react";
 import { useTranslation } from "react-i18next";
+import { I18nKey } from "#/i18n/declaration";
 
 type Label = "model" | "agent" | "language";
 
@@ -58,7 +58,11 @@ export function AutocompleteCombobox({
         label={t(LABELS[ariaLabel])}
         placeholder={t(PLACEHOLDERS[ariaLabel])}
         defaultItems={items}
-        defaultSelectedKey={defaultKey}
+        defaultInputValue={
+          // Find the label for the default key, otherwise use the default key itself
+          // This is useful when the default key is not in the list of items, in the case of a custom LLM model
+          items.find((item) => item.value === defaultKey)?.label || defaultKey
+        }
         isDisabled={disabled}
         allowsCustomValue={allowCustomValue}
         onInputChange={(value) => {