diff --git a/packages/signaldb/__tests__/sync/SyncManager.spec.ts b/packages/signaldb/__tests__/sync/SyncManager.spec.ts
index 89d0a37a..6cae5dc9 100644
--- a/packages/signaldb/__tests__/sync/SyncManager.spec.ts
+++ b/packages/signaldb/__tests__/sync/SyncManager.spec.ts
@@ -510,6 +510,42 @@ it('should handle error in remote changes with data', async () => {
   expect(onError).toHaveBeenCalledWith({ name: 'test' }, new Error('Pull failed'))
 })
 
+it('should sync second time if there were changes during sync', async () => {
+  const mockPull = vi.fn<() => Promise<LoadResponse<TestItem>>>().mockResolvedValue({
+    items: [{ id: '1', name: 'Test Item' }],
+  })
+
+  const mockPush = vi.fn<(options: any, pushParams: any) => Promise<void>>()
+    .mockResolvedValue()
+
+  const onRemoteChangeHandler = vi.fn<(data?: LoadResponse<TestItem>) => void | Promise<void>>()
+  const onError = vi.fn()
+  const syncManager = new SyncManager({
+    onError,
+    persistenceAdapter: () => memoryPersistenceAdapter([]),
+    pull: mockPull,
+    push: mockPush,
+    registerRemoteChange: (_options, onRemoteChange) => {
+      onRemoteChangeHandler.mockImplementation(onRemoteChange)
+    },
+  })
+
+  const mockCollection = new Collection<TestItem, string, any>()
+
+  syncManager.addCollection(mockCollection, { name: 'test' })
+
+  // Simulate a remote change
+  const promise = onRemoteChangeHandler({ items: [{ id: '2', name: 'Remote Item' }] })
+  mockCollection.insert({ id: '1', name: 'Test Item' })
+  await expect(promise).resolves.not.toThrow()
+  expect(onError).toHaveBeenCalledTimes(0)
+
+  // wait to next tick
+  await new Promise((resolve) => { setTimeout(resolve, 0) })
+
+  expect(mockCollection.find().fetch()).toEqual([{ id: '1', name: 'Test Item' }])
+})
+
 it('should sync after a empty remote change was received', async () => {
   const mockPull = vi.fn<() => Promise<LoadResponse<TestItem>>>().mockResolvedValue({
     items: [{ id: '1', name: 'Test Item' }],
@@ -818,3 +854,62 @@ it('should not leave any remote changes after successful pull', async () => {
   // @ts-expect-error - private property
   expect(syncManager.remoteChanges.length).toBe(0)
 })
+
+it('should reset if syncmanager snapshot and collection are not in sync', async () => {
+  const mockPull = vi.fn<() => Promise<LoadResponse<TestItem>>>().mockResolvedValue({
+    items: [
+      { id: '1', name: 'Test Item' },
+      { id: '2', name: 'Test Item 2' },
+    ],
+  })
+
+  const mockPush = vi.fn<(options: any, pushParams: any) => Promise<void>>()
+    .mockResolvedValue()
+  const onError = vi.fn()
+
+  const syncManager = new SyncManager({
+    onError,
+    persistenceAdapter: () => memoryPersistenceAdapter([]),
+    pull: mockPull,
+    push: mockPush,
+  })
+
+  const mockCollection = new Collection<TestItem, string, any>({
+    memory: [
+      { id: '1', name: 'Test Item' },
+      { id: 'x', name: 'Test Item 3' },
+    ],
+  })
+
+  syncManager.addCollection(mockCollection, { name: 'test' })
+
+  await syncManager.sync('test')
+  expect(mockCollection.find().fetch()).toEqual([
+    { id: '1', name: 'Test Item' },
+    { id: '2', name: 'Test Item 2' },
+  ])
+
+  // @ts-expect-error - private property
+  syncManager.snapshots.updateOne({ collectionName: 'test' }, {
+    // monkey patch the snapshot and add one item
+    $set: {
+      items: [
+        { id: '1', name: 'Test Item' },
+        { id: '2', name: 'Test Item 2' },
+        { id: 'xxx', name: 'Test Item xxx' },
+      ],
+    },
+  })
+
+  await syncManager.sync('test')
+  expect(mockCollection.find().fetch()).toEqual([
+    { id: '1', name: 'Test Item' },
+    { id: '2', name: 'Test Item 2' },
+  ])
+
+  expect(onError).not.toHaveBeenCalled()
+  expect(mockPull).toHaveBeenCalled()
+
+  // @ts-expect-error - private property
+  expect(syncManager.remoteChanges.length).toBe(0)
+})
diff --git a/packages/signaldb/__tests__/sync/getSnapshot.spec.ts b/packages/signaldb/__tests__/sync/getSnapshot.spec.ts
index e9afc347..0fc77113 100644
--- a/packages/signaldb/__tests__/sync/getSnapshot.spec.ts
+++ b/packages/signaldb/__tests__/sync/getSnapshot.spec.ts
@@ -100,3 +100,17 @@ it('should handle undefined lastSnapshot and apply changes', () => {
   const result = getSnapshot(lastSnapshot, data)
   expect(result).toEqual([{ id: 3, name: 'Item 3' }])
 })
+
+it('should upsert changes', () => {
+  const lastSnapshot: TestItem[] = [{ id: 2, name: 'Item 2' }]
+  const data: LoadResponse<TestItem> = {
+    changes: {
+      added: [{ id: 2, name: 'Item 23' }],
+      modified: [{ id: 3, name: 'Item 3' }],
+      removed: [],
+    },
+  }
+
+  const result = getSnapshot(lastSnapshot, data)
+  expect(result).toEqual([{ id: 2, name: 'Item 23' }, { id: 3, name: 'Item 3' }])
+})
diff --git a/packages/signaldb/src/SyncManager/index.ts b/packages/signaldb/src/SyncManager/index.ts
index 335ad21f..e93d9bab 100644
--- a/packages/signaldb/src/SyncManager/index.ts
+++ b/packages/signaldb/src/SyncManager/index.ts
@@ -506,6 +506,7 @@ export default class SyncManager<
         collection.updateOne({ id: itemId } as Record<string, any>, modifier)
       },
       remove: (itemId) => {
+        if (!collection.findOne({ id: itemId } as Record<string, any>)) return
         this.remoteChanges.push({
           collectionName: name,
           type: 'remove',
@@ -550,37 +551,39 @@ export default class SyncManager<
             force: true,
             onlyWithChanges: true,
           })
-        } else {
-          // if there are no unsynced changes apply the last snapshot
-          // to make sure that collection and snapshot are in sync
-
-          // find all items that are not in the snapshot
-          const nonExistingItemIds = collection.find({
-            id: { $nin: snapshot.map(item => item.id) } as any,
-          }).map(item => item.id) as IdType[]
-
-          // find all items that are in the snapshot but not in the collection
-          const existingItemIds = new Set(snapshot
-            .filter(item => collection.find({ id: item.id as any }).count() > 0)
-            .map(item => item.id))
-
-          collection.batch(() => {
-            // update all items that are in the snapshot
-            snapshot.forEach((item) => {
-              const itemExists = existingItemIds.has(item.id)
-              if (itemExists) {
-                collection.updateOne({ id: item.id as any }, { $set: item })
-              } else {
-                collection.insert(item)
-              }
-            })
+          return
+        }
 
-            // remove all items that are not in the snapshot
-            nonExistingItemIds.forEach((id) => {
-              collection.removeOne({ id: id as any })
-            })
+        // if there are no unsynced changes apply the last snapshot
+        // to make sure that collection and snapshot are in sync
+
+        // find all items that are not in the snapshot
+        const nonExistingItemIds = collection.find({
+          id: { $nin: snapshot.map(item => item.id) } as any,
+        }).map(item => item.id) as IdType[]
+
+        // find all items that are in the snapshot but not in the collection
+        const existingItemIds = new Set(collection.find({
+          id: { $in: snapshot.map(item => item.id) } as any,
+        }).map(item => item.id) as IdType[])
+
+        collection.batch(() => {
+          // update all items that are in the snapshot
+          snapshot.forEach((item) => {
+            const itemExists = existingItemIds.has(item.id)
+            /* istanbul ignore else -- @preserve */
+            if (itemExists) {
+              collection.updateOne({ id: item.id as any }, { $set: item })
+            } else { // this case should never happen
+              collection.insert(item)
+            }
           })
-        }
+
+          // remove all items that are not in the snapshot
+          nonExistingItemIds.forEach((id) => {
+            collection.removeOne({ id: id as any })
+          })
+        })
       })
   }
 }