"RSS" bookmarks disappeared again on Firefox on Ubuntu (disable autosync). I have to disable EverSync.

I disable autosync. When I make "Manual Sync - Merge" everthing is ok.

Autosync is enable.
Example bookmark:

• Name: stackideas.com
• Feed url: http://stackideas.com/blog/latest?format=feed
• Site url: http://stackideas.com/blog/latest

Another bookmark:

• Name: gosc.pl
• Feed url: http://gosc.pl/rss/rtr/c7a21.Aktualnosci-z-Gosciem-Niedzielnym
• Site url: http://gosc.pl/

Yes, all rss bookmarks was in "RSS" folder in toolbar. RSS bookmarks disappeared, folder "RSS" exists but is empty.