The cloud icon says "syncing 1 photo", but nothing on the sync Activity screen

My Lightroom 0n PC always says its syncing 1 photo and there is a blue circle over the cloud icon in the top right corner of the screen. But on the "Lightroon Sync" Tab of the Preferences it says there is nothig uploading or downloading. Its been like this for maybe a year.

I've had the sync hang up several times and I've managed to get it unstuck, but it never clears the last 1 photo syncing message.

Thanks if anyone can tell me how to clear this small annoyance.

J