Bookmark sync to firefox not working
Can't get iCloud Bookmarks to sync on Windows 7 with Firefox v57
No, I have tried many different workarounds including reinstalling current and prior versions of iCloud, clean install of Firefox, disabling firewalls etc. I was able to get it to work briefly with and image from several months ago (with Firefox v54) but then it stopped working. I suspect that the extension updated automatically shortly after the restore and caused it to stop working. I believe the problem may be with the Firefox extension. We may just have to wait for Apple to fix.
I thought the detail you provided was interesting - maybe someone from Apple will notice it.