I loved this extension. Up until a few weeks ago, the extension and Windows app used to work just fine with Firefox and Google Chrome. Now it will only sync with Chrome and I can't, for the life of me, get the Windows app to connect to Firefox.

not good.

其实可以用，但是会提示没有安装，但明明可以同步火狐

Crap shoot! Good when it works...Bookmark sync with FF stopped working after iOS 15. Odd behavior on Windows 10 (from the store) client when changing settings attempting to troubleshoot. Change bookmark settings and photo settings get changed. Sadly, no support available as Apple is well known for their lack of support to Windows versions of their products.

Doesn't work after it had worked for several months

无法跳转到软件，导致无法使用。

This doesn't work! Is it Firefox or is it iCloud? iCloud doen't recognize that the extension is already installed in Firefox. As such you cannot sync Safari bookmarks with Firefox. Apparently this 'bug' has been around for a while but as yet it's not been fixed.