diff --git a/resources/js/components/inputs/relationship/RelationshipInput.vue b/resources/js/components/inputs/relationship/RelationshipInput.vue
index 7d010f0c4eb..a6bb3dd7d9c 100644
--- a/resources/js/components/inputs/relationship/RelationshipInput.vue
+++ b/resources/js/components/inputs/relationship/RelationshipInput.vue
@@ -300,6 +300,16 @@ export default {
             this.$emit('item-data-updated', data);
         },
 
+        value(value) {
+            if (this.initializing || this.loading) return;
+
+            // A value set from outside (e.g. a save response normalizing a typed term) may
+            // reference an id we have no data for yet, which would render as a raw id.
+            if (value?.some((selection) => !this.data?.find((item) => item.id == selection))) {
+                this.getDataForSelections(value);
+            }
+        },
+
         items(items, oldItems) {
             if (items.length > 0 && oldItems.length === 0) {
                 if (this.canReorder) {
diff --git a/resources/js/components/inputs/relationship/SelectField.vue b/resources/js/components/inputs/relationship/SelectField.vue
index ffe66b49924..6bedba8c661 100644
--- a/resources/js/components/inputs/relationship/SelectField.vue
+++ b/resources/js/components/inputs/relationship/SelectField.vue
@@ -7,7 +7,7 @@
             :max-selections="maxSelections"
             :model-value="items.map((item) => item.id)"
             :multiple
-            :options
+            :options="comboboxOptions"
             :placeholder="__(config.placeholder) || __('Choose...')"
             :read-only="readOnly"
             :taggable="isTaggable"
@@ -95,6 +95,14 @@ export default {
 			return JSON.stringify({ ...this.parameters, url: this.url });
 	    },
 
+        comboboxOptions() {
+            // Combobox resolves the selected label from this list, so a selected item missing
+            // from it (e.g. a just-created term) would otherwise display as its raw id.
+            const missing = this.items.filter((item) => !this.options.some((option) => option.id === item.id));
+
+            return [...this.options, ...missing];
+        },
+
         noOptionsText() {
             return this.typeahead && !this.requested ? __('Start typing to search.') : __('No options to choose from.');
         },
diff --git a/resources/js/tests/components/inputs/relationship/RelationshipInput.test.js b/resources/js/tests/components/inputs/relationship/RelationshipInput.test.js
index bc2eda8a64e..069793e9583 100644
--- a/resources/js/tests/components/inputs/relationship/RelationshipInput.test.js
+++ b/resources/js/tests/components/inputs/relationship/RelationshipInput.test.js
@@ -239,3 +239,41 @@ describe('RelationshipInput in-flight request deduplication', () => {
         b.unmount();
     });
 });
+
+describe('RelationshipInput refetches item data for unresolved values', () => {
+    test('fetches item data when the value prop changes to include an id with no matching data', async () => {
+        const d = deferred();
+        const post = vi.fn(() => d.promise);
+
+        const wrapper = mountInput({ axiosPost: post, itemDataUrl: '/test/stale-value' });
+        await flushPromises();
+
+        await wrapper.setProps({ value: ['taxonomy::bob'] });
+        await flushPromises();
+
+        expect(post).toHaveBeenCalledWith(
+            '/test/stale-value',
+            { site: 'default', selections: ['taxonomy::bob'] },
+            expect.anything(),
+        );
+
+        d.resolve({ data: { data: [] } });
+        await flushPromises();
+
+        wrapper.unmount();
+    });
+
+    test('does not refetch when the new value is already covered by existing data', async () => {
+        const post = vi.fn(() => Promise.resolve({ data: { data: [] } }));
+
+        const wrapper = mountInput({ axiosPost: post, itemDataUrl: '/test/stale-value-known' });
+        await flushPromises();
+
+        await wrapper.setProps({ data: [{ id: '1', title: 'One' }], value: ['1'] });
+        await flushPromises();
+
+        expect(post).not.toHaveBeenCalled();
+
+        wrapper.unmount();
+    });
+});
diff --git a/resources/js/tests/components/inputs/relationship/SelectField.test.js b/resources/js/tests/components/inputs/relationship/SelectField.test.js
new file mode 100644
index 00000000000..322f3f5216b
--- /dev/null
+++ b/resources/js/tests/components/inputs/relationship/SelectField.test.js
@@ -0,0 +1,53 @@
+import { mount } from '@vue/test-utils';
+import { describe, expect, test, vi } from 'vitest';
+
+vi.mock('@inertiajs/vue3', () => ({
+    router: { on: () => () => {} },
+}));
+
+globalThis.__ = (key) => key;
+
+import { data_get } from '@/bootstrap/globals.js';
+globalThis.data_get = data_get;
+
+import SelectField from '@/components/inputs/relationship/SelectField.vue';
+
+const stubs = {
+    Combobox: true,
+    StatusIndicator: true,
+};
+
+function mountSelectField({ items = [] } = {}) {
+    return mount(SelectField, {
+        props: {
+            items,
+            url: '/test/select-field',
+            config: {},
+        },
+        global: {
+            mocks: {
+                $axios: { get: () => Promise.resolve({ data: { data: [] } }) },
+            },
+            stubs,
+        },
+    });
+}
+
+describe('SelectField comboboxOptions', () => {
+    test('includes a selected item missing from the fetched options list', () => {
+        const wrapper = mountSelectField({ items: [{ id: 'tags::bob', title: 'Bob' }] });
+
+        expect(wrapper.vm.comboboxOptions).toContainEqual({ id: 'tags::bob', title: 'Bob' });
+
+        wrapper.unmount();
+    });
+
+    test('does not duplicate an item already present in the fetched options list', async () => {
+        const wrapper = mountSelectField({ items: [{ id: '1', title: 'One' }] });
+        await wrapper.setData({ options: [{ id: '1', title: 'One' }] });
+
+        expect(wrapper.vm.comboboxOptions).toEqual([{ id: '1', title: 'One' }]);
+
+        wrapper.unmount();
+    });
+});