Hello, yes I also fell on that recentlyl, it seems the behavior of FF bookmark search API changed a bit and is now returning two special folders I was not seeing before, and which are not expected (namely the "Tags" special folder ... but also the Mobile bookmarks special folder even when it is empty).

Since they are not expected, BSP2 believes there is a de-synchronization with the FF DB of bookmarks, and attempts a reload.

This is corrected in 2.0.76 which will be out soon ... I filtered out those two items when appropriate from the search result gotten from FF API.
Thanks aaFn.

====================== Update ===================
2.0.76 is out now with the fix for extended search responses.
Should be all ok now, sorry for the inconvenience, aaFn.