Sync not detecting changes

I have recently started having a bug where sync does not work.

Problem:

I start Lightroom Classic (version 13.0.1), the sync checkmark is green and there are no pending sync jobs or errors. But any changes I make to synced collections never sync, they are not even detected.

If I go to Preferences -> Lightroom Sync it says "Uploads: None" and the Sync Activity area is empty (0 uploading, 0 downloading, 0 pending).

This despite having many uploads, and having made changes to synced collections.

No matter how many times I restart Lightroom or the computer, it still says none and no sync activity.

The workaround:

I have discovered one way that reliably fixes this issue, and that is to hold down alt in the same "Lightroom Sync"-dialog, and press "Generate Diagnostic Report".

Something in the process that generates the diagnostic report fixes sync. After generating the report when I reopen preferences, it shows "Uploads: 1312" and the changes I've made to synced collections start to sync.

The problem then reoccurs if I close Lightroom Classic and open it again.

So, I have a workaround to the problem, but maybe this can help someone else experiencing the same issue. And hopefully it can be fixed in a future release.