Your comments

have updated the extension to version 23.2.1 and the problem persists exactly as three months ago.

I have updated the extension to version 23.1.7 and the problem persists exactly as two months ago.

I have updated the extension to version 23.1.4 and the problem persists.

I have noticed that when I sync (after updating the cloud information with Firefox), now the extension deletes all bookmarks locally and stops.
With the previous version, after deleting, the extension would download 80 bookmarks before stopping.
This behaviour was similar in both Chrome and Edge (as expected).

I've made similar test at home with same results.

I've been doing some more test and at work, neither Chrome or Edge plugin synchronize at all. When i add a bookmark, it is not uploaded to the cloud. I have to upload ALL. And when i delete a bookmark, it is not deleted at the cloud. I hace to upload ALL again.
Tith Firefox i do not have any issue, some times faster some times slower, but at least content is the same locally and at the cloud.
In a couple of hours I'll repeat the test at home.

I've updated to version 23.1.3 with same results. Pehaps synchonizations do not fail as before, but i can not be sure

Image 2595

This is the messaga i ALWAYS see in Chrome and EDGE. I can synch 90% times in Chrome without issues, but 50% of times when I try the same in EDGE, some times EDGE deletes many cloud bookmarks other it does not load every cloud ones and deletes half local ones. I keeping always a local backupo copy (once i get a good state).

Thank you very much for the suggestion, but I don't need to check the synchronisation settings of the browsers, as I don't have it activated in any of them. In Firefox I have NO problem. It is in Chromium-based browsers where I get the warning mentioned above, and where sometimes the bookmark synchronisation "goes crazy".
Regards, Fernando