After digging around, I stumbled into a solution and want to share my experience. A few days back, after reorganizing my bookmarks, I noticed these changes did not sync to my other computers. I followed the recommendations for [[https://support.mozilla.org/en-US/questions/1219438]] [https://support.mozilla.org/en-US/questions/1219438 deleting certain files to restart the sync], a recommendation to create new accounts, and [https://support.mozilla.org/en-US/questions/1294263 reinstalling Firefox]. None of these worked. What did work was: 1. I backed up my bookmarks to both html and json, just in case. 2. I uninstalled Firefox completely, on two of my three computers, then reinstalled. 3. I created a new account. While this is not necessary, I discovered Firefox does allow Gmail's [https://www.idownloadblog.com/2018/12/19/gmail-email-address-tricks/ email address tricks] after a plus sign (example: firefox+randomword (at) gmail.com). I've been doing this more and more for extra security so a hacker can't use my regular email as a starting point. 4. With all computers logged in, I imported my bookmarks and synced. This solved the bookmark issues. But I've lost my history. I logged into my old account to discover my history was erased as expected. Searching for a solution turned up a Windows tool, but also a mention to import to another browser from which to import into my new account. I downloaded Opera and imported my history locally. 5. In Firefox, logged into my new account, I prepared to import my browsing history back into the new account. Lo and behold, a Firefox pop-up asked if I wanted to merge my old Firefox account sync data into my new account. I did, and everything worked-meaning I did not have to import from Opera. For admins: It's great there was a tool to allow me to cross import/merge accounts. But why didn't that come up in help docs? And why can't I trigger this myself? Would have made everything so much easier. That said, I'm happy it's all working now and my imports are syncing across my devices. If anyone has any questions, as this was hastily written while my kids run around, please ping me and I'll answer as soon as possible.