diff --git a/packages/ui/src/elements/WhereBuilder/Condition/Relationship/optionsReducer.spec.ts b/packages/ui/src/elements/WhereBuilder/Condition/Relationship/optionsReducer.spec.ts
new file mode 100644
index 00000000000..30f156f40ec
--- /dev/null
+++ b/packages/ui/src/elements/WhereBuilder/Condition/Relationship/optionsReducer.spec.ts
@@ -0,0 +1,132 @@
+import { describe, expect, it } from 'vitest'
+
+import optionsReducer from './optionsReducer.js'
+import type { Option } from './types.js'
+
+const mockI18n = {
+  t: (key: string) => key,
+} as any
+
+const mockCollection = {
+  admin: { useAsTitle: 'title' },
+  labels: { plural: 'Posts' },
+} as any
+
+describe('optionsReducer', () => {
+  describe('ADD — single relation', () => {
+    it('deduplicates options when the same doc is loaded twice', () => {
+      const initial: Option[] = [{ label: 'Post A', value: 'id-1' }]
+
+      const result = optionsReducer(initial, {
+        type: 'ADD',
+        collection: mockCollection,
+        data: {
+          docs: [
+            { id: 'id-1', title: 'Post A' }, // already in state
+            { id: 'id-2', title: 'Post B' }, // new
+          ],
+          totalDocs: 2,
+          limit: 10,
+          totalPages: 1,
+          page: 1,
+          pagingCounter: 1,
+          hasPrevPage: false,
+          hasNextPage: false,
+          prevPage: null,
+          nextPage: null,
+        },
+        hasMultipleRelations: false,
+        i18n: mockI18n,
+        relation: 'posts',
+      })
+
+      expect(result).toHaveLength(2)
+      expect(result.map((o) => o.value)).toEqual(['id-1', 'id-2'])
+    })
+
+    it('appends all docs when state is empty', () => {
+      const result = optionsReducer([], {
+        type: 'ADD',
+        collection: mockCollection,
+        data: {
+          docs: [
+            { id: 'id-1', title: 'Post A' },
+            { id: 'id-2', title: 'Post B' },
+          ],
+          totalDocs: 2,
+          limit: 10,
+          totalPages: 1,
+          page: 1,
+          pagingCounter: 1,
+          hasPrevPage: false,
+          hasNextPage: false,
+          prevPage: null,
+          nextPage: null,
+        },
+        hasMultipleRelations: false,
+        i18n: mockI18n,
+        relation: 'posts',
+      })
+
+      expect(result).toHaveLength(2)
+    })
+  })
+
+  describe('ADD — multiple relations (grouped options)', () => {
+    it('deduplicates sub-options within a group when the same doc is loaded twice', () => {
+      const initial: Option[] = [
+        {
+          label: 'Posts',
+          value: undefined as any,
+          options: [{ label: 'Post A', value: 'id-1', relationTo: 'posts' }],
+        },
+      ]
+
+      const result = optionsReducer(initial, {
+        type: 'ADD',
+        collection: { ...mockCollection, labels: { plural: 'Posts' } },
+        data: {
+          docs: [
+            { id: 'id-1', title: 'Post A' }, // duplicate
+            { id: 'id-2', title: 'Post B' }, // new
+          ],
+          totalDocs: 2,
+          limit: 10,
+          totalPages: 1,
+          page: 1,
+          pagingCounter: 1,
+          hasPrevPage: false,
+          hasNextPage: false,
+          prevPage: null,
+          nextPage: null,
+        },
+        hasMultipleRelations: true,
+        i18n: { t: () => 'Posts' } as any,
+        relation: 'posts',
+      })
+
+      const group = result.find((o) => o.options)
+      expect(group?.options).toHaveLength(2)
+      expect(group?.options?.map((o) => o.value)).toEqual(['id-1', 'id-2'])
+    })
+  })
+
+  describe('CLEAR', () => {
+    it('returns empty array when field is required', () => {
+      const result = optionsReducer(
+        [{ label: 'Post A', value: 'id-1' }],
+        { type: 'CLEAR', required: true, i18n: mockI18n },
+      )
+      expect(result).toEqual([])
+    })
+
+    it('returns none option when field is not required', () => {
+      const result = optionsReducer(
+        [{ label: 'Post A', value: 'id-1' }],
+        { type: 'CLEAR', required: false, i18n: mockI18n },
+      )
+      expect(result).toHaveLength(1)
+      expect(result[0]?.value).toBe('null')
+    })
+  })
+})
diff --git a/packages/ui/src/elements/WhereBuilder/Condition/Relationship/optionsReducer.ts b/packages/ui/src/elements/WhereBuilder/Condition/Relationship/optionsReducer.ts
index bcfddfe5fdc..b373d4e75d5 100644
--- a/packages/ui/src/elements/WhereBuilder/Condition/Relationship/optionsReducer.ts
+++ b/packages/ui/src/elements/WhereBuilder/Condition/Relationship/optionsReducer.ts
@@ -9,7 +9,7 @@ const reduceToIDs = (options) =>
       return [...ids, ...reduceToIDs(option.options)]
     }
 
-    return [...ids, option.id]
+    return [...ids, option.value ?? option.id]
   }, [])
 
 const optionsReducer = (state: Option[], action: Action): Option[] => {