As for the sync loop bug, I couldn’t reproduce it yet, but that doesn’t mean much. It appeared on some days, but not on others, seemingly independently of my actions. I’ll keep an eye on it and report back once it reoccurs or I am confident that it won’t.
Unfortunately, I had no trouble reproducing the other (?) bug, where the sync button is blue after the first sync upon start. It might be comeplety unrelated to the first one. I didn’t actually ascertain that it has the same cause.