Edge sync fails after restart — MSA key error

I have exactly the same problem. This is a new issue for me. Edge Sync had been working perfectly until recently.

After a Windows restart, Edge remains stuck on "Syncing…" indefinitely. Existing bookmarks are still visible, but any new bookmark I add is not synced to my other devices, including my iPhone.

I found a reliable workaround:

• Before shutting down or restarting Windows, I sign out of my Edge profile.
• I restart Windows.
• I sign back into Edge.

After doing this, sync works again.

If I keep the Edge profile signed in when Windows restarts, the issue returns and Edge stays stuck on "Syncing…".

I can reproduce this behavior consistently.

From edge://sync-internals, I observed the following states while the issue is occurring:

• Transport State: Initializing
• Sync Engine: NotStarted
• DataType Manager State: Stopped
• Download Key Result: Fail
• Set Key Result: Fail

At the same time:

• Authentication succeeds
• Tokens are successfully obtained
• Existing bookmarks are downloaded from the cloud

However, newly created bookmarks are never uploaded and do not appear on my other devices.