Each time I startup my mac I get an error warning "To avoid conflicts with your editing of this Collection, automatic Syncing with Clients is suspended until you finish and close this window."

This started about a month ago and I'm not sure what I changed but it happens every time now - not sure if an error or just that I'm not using BookMacster correctly anymore / forgot how to use it? I will try to insert a composite screenshot for settings but am not sure how to do that on this board, in case it doesn't work: Full Syncing (simple) defaults, and, with Sorting also checked, import from / export to primary browser, export only to secondary browser.

When the warning started, I manually imported all bookmarks from my primary browser and re-set syncing to Simple, with defaults - I found that no changes for months had been recorded into the Collection (I rarely use the secondary browser). I always select ask what to do if nothing opens on launch, and, then pick Backbround bookmacster after re-starting sync (which is now remaining on yellow). The mac I use this on has macOS Catalina 10.15.7 and 4 user accounts on the same mac. I have been using BookMacster for years on 3 user accounts, these three have *different* Collections documents: at work, Firefox and a work-01 collection, Firefox as primary (import only, sort; export to Firefox and Safari secondary); at home-1, Safari, Firefox; Safari primary also uses iCloud - only Safari using iCloud; home-2 - Firefox, Vivaldi, Firefox primary.

Any ideas?

This forum won't let me post an image as a forum new user but a screenshot composite showing settings is at short url ending in 3sKkEX9 at the  bit  dot  ly  shortener