diff --git a/frontend/src/components/AccessListSelector.tsx b/frontend/src/components/AccessListSelector.tsx
index 7c059f57..d359d87a 100644
--- a/frontend/src/components/AccessListSelector.tsx
+++ b/frontend/src/components/AccessListSelector.tsx
@@ -31,8 +31,8 @@ function resolveAccessListToken(value: number | string | null | undefined): stri
     return trimmed;
   }
 
-  const parsed = Number.parseInt(trimmed, 10);
-  if (!Number.isNaN(parsed)) {
+  if (/^\d+$/.test(trimmed)) {
+    const parsed = Number.parseInt(trimmed, 10);
     return `id:${parsed}`;
   }
 
@@ -46,7 +46,7 @@ function getOptionToken(acl: { id?: number | string; uuid?: string }): string |
 
   if (typeof acl.id === 'string') {
     const trimmed = acl.id.trim();
-    if (trimmed !== '') {
+    if (trimmed !== '' && /^\d+$/.test(trimmed)) {
       const parsed = Number.parseInt(trimmed, 10);
       if (!Number.isNaN(parsed)) {
         return `id:${parsed}`;
@@ -89,8 +89,8 @@ export default function AccessListSelector({ value, onChange }: AccessListSelect
       return;
     }
 
-    const numericId = Number.parseInt(newValue, 10);
-    if (!Number.isNaN(numericId)) {
+    if (/^\d+$/.test(newValue)) {
+      const numericId = Number.parseInt(newValue, 10);
       onChange(numericId);
       return;
     }
diff --git a/frontend/src/components/ProxyHostForm.tsx b/frontend/src/components/ProxyHostForm.tsx
index 85afdd47..c0326ebf 100644
--- a/frontend/src/components/ProxyHostForm.tsx
+++ b/frontend/src/components/ProxyHostForm.tsx
@@ -148,6 +148,10 @@ function normalizeNullableID(value: unknown): number | null | undefined {
       return null
     }
 
+    if (!/^\d+$/.test(trimmed)) {
+      return undefined
+    }
+
     const parsed = Number.parseInt(trimmed, 10)
     return Number.isNaN(parsed) ? undefined : parsed
   }
@@ -173,8 +177,8 @@ function resolveSelectToken(value: number | string | null | undefined): string {
     return trimmed
   }
 
-  const parsed = Number.parseInt(trimmed, 10)
-  if (!Number.isNaN(parsed)) {
+  if (/^\d+$/.test(trimmed)) {
+    const parsed = Number.parseInt(trimmed, 10)
     return `id:${parsed}`
   }
 
@@ -195,8 +199,12 @@ function resolveTokenToFormValue(value: string): number | string | null {
     return value.slice(5)
   }
 
-  const parsed = Number.parseInt(value, 10)
-  return Number.isNaN(parsed) ? value : parsed
+  if (/^\d+$/.test(value)) {
+    const parsed = Number.parseInt(value, 10)
+    return Number.isNaN(parsed) ? value : parsed
+  }
+
+  return value
 }
 
 function getEntityToken(entity: { id?: number; uuid?: string }): string | null {
diff --git a/frontend/src/components/__tests__/AccessListSelector.test.tsx b/frontend/src/components/__tests__/AccessListSelector.test.tsx
index 90a69963..05f9f955 100644
--- a/frontend/src/components/__tests__/AccessListSelector.test.tsx
+++ b/frontend/src/components/__tests__/AccessListSelector.test.tsx
@@ -163,4 +163,38 @@ describe('AccessListSelector', () => {
 
     expect(mockOnChange).toHaveBeenCalledWith(7);
   });
+
+  it('keeps a UUID-leading-digit selection stable in the trigger', () => {
+    const uuid = '9f63b8c9-1d26-4b2f-a2c8-001122334455';
+    const mockLists = [
+      {
+        id: undefined,
+        uuid,
+        name: 'UUID Digit Prefix ACL',
+        description: 'UUID-only ACL payload',
+        type: 'whitelist',
+        ip_rules: '[]',
+        country_codes: '',
+        local_network_only: false,
+        enabled: true,
+        created_at: '2024-01-01',
+        updated_at: '2024-01-01',
+      },
+    ];
+
+    vi.mocked(useAccessListsHook.useAccessLists).mockReturnValue({
+      data: mockLists as unknown as AccessList[],
+    } as unknown as ReturnType<typeof useAccessListsHook.useAccessLists>);
+
+    const mockOnChange = vi.fn();
+    const Wrapper = createWrapper();
+
+    render(
+      <Wrapper>
+        <AccessListSelector value={uuid} onChange={mockOnChange} />
+      </Wrapper>
+    );
+
+    expect(screen.getByRole('combobox', { name: /Access Control List/i })).toHaveTextContent('UUID Digit Prefix ACL');
+  });
 });
diff --git a/frontend/src/components/__tests__/ProxyHostForm-dropdown-changes.test.tsx b/frontend/src/components/__tests__/ProxyHostForm-dropdown-changes.test.tsx
index c30a7141..1662a29c 100644
--- a/frontend/src/components/__tests__/ProxyHostForm-dropdown-changes.test.tsx
+++ b/frontend/src/components/__tests__/ProxyHostForm-dropdown-changes.test.tsx
@@ -559,7 +559,7 @@ describe('ProxyHostForm Dropdown Change Bug Fix', () => {
       {
         ...mockAccessLists[0],
         id: undefined,
-        uuid: 'acl-uuid-only',
+        uuid: '9f63b8c9-1d26-4b2f-a2c8-001122334455',
         name: 'UUID Office Network',
       },
     ]