diff --git a/src/components/AppNavigation/GroupNavigationItem.vue b/src/components/AppNavigation/GroupNavigationItem.vue
index 162728691b..9eaf91c300 100644
--- a/src/components/AppNavigation/GroupNavigationItem.vue
+++ b/src/components/AppNavigation/GroupNavigationItem.vue
@@ -163,19 +163,22 @@ export default {
 		async onDrop(event, group) {
 			try {
 				const contactFromDropData = JSON.parse(event.dataTransfer.getData('item'))
-				const contactFromStore = this.$store.getters.getContact(Buffer.from(`${contactFromDropData.uid}~${contactFromDropData.addressbookId}`, 'utf-8').toString('base64'))
-				if (contactFromStore && !this.isInGroup(contactFromStore.groups, group.id)) {
-					const contact = this.$store.getters.getContact(Buffer.from(`${contactFromDropData.uid}~${contactFromDropData.addressbookId}`, 'utf-8').toString('base64'))
+				const contactId = Buffer.from(`${contactFromDropData.uid}~${contactFromDropData.addressbookId}`, 'utf-8').toString('base64')
+				let contact = this.$store.getters.getContact(contactId)
+				if (!contact) {
+					return
+				}
+
+				await this.$store.dispatch('fetchFullContact', { contact })
+				contact = this.$store.getters.getContact(contactId)
+
+				if (!this.isInGroup(contact.groups, group.id)) {
+					contact.groups = [...contact.groups, group.name]
 					await this.$store.dispatch('updateContactGroups', {
-						groupNames: [...contactFromStore.groups, group.name],
+						groupNames: contact.groups,
 						contact,
 					})
-					const localContact = Object.assign(
-						Object.create(Object.getPrototypeOf(contact)),
-						contact,
-					)
-					localContact.groups = [...contactFromStore.groups, group.name]
-					await this.$store.dispatch('updateContact', localContact)
+					await this.$store.dispatch('updateContact', contact)
 				}
 			} catch (e) {
 				console.error(e)
diff --git a/tests/javascript/models/contact.test.js b/tests/javascript/models/contact.test.js
index c4c429e46a..53c26b13b4 100644
--- a/tests/javascript/models/contact.test.js
+++ b/tests/javascript/models/contact.test.js
@@ -60,3 +60,37 @@ describe('Test stripping quotes from TYPE', () => {
 	})
 
 })
+
+describe('Test groups setter', () => {
+
+	let contact
+
+	beforeEach(() => {
+		contact = new Contact(
+			'BEGIN:VCARD\nVERSION:3.0\nUID:123456789-123465-123456-123456789\nFN:Test contact\nEND:VCARD',
+		)
+	})
+
+	test('groups setter updates jCal so the group is included in serialization', () => {
+		contact.groups = ['Friends']
+
+		expect(contact.groups).toEqual(['Friends'])
+		expect(contact.vCard.toString()).toContain('CATEGORIES:Friends')
+	})
+
+	test('groups setter replaces existing groups', () => {
+		contact.groups = ['OldGroup']
+		contact.groups = ['NewGroup']
+
+		expect(contact.groups).toEqual(['NewGroup'])
+	})
+
+	test('groups setter with empty array removes categories property', () => {
+		contact.groups = ['SomeGroup']
+		contact.groups = []
+
+		expect(contact.groups).toEqual([])
+		expect(contact.vCard.hasProperty('categories')).toBe(false)
+	})
+
+})
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