I-Firefox Isithangami Sokwesekwa

I have 3 desktops and 2 laptops with Firefox sync turned on. Occasionally the bookmarks on all devices are synced with an older version of bookmarks. I'm guessing it's from one of the laptops that hasn't been turned on in a few weeks and now is on. Is there not a way to prevent an old set of bookmarks from replacing a known 'good' set of bookmarks? Thankfully I have my bookmarks backup turned on and can restore them but would like to know if there is a solution to keeping bookmarks current and stable on all devices, even those devices that aren't regularly used.

I have two desktop computers and both Firefox accounts are in my name. I have had this site up for years. Now when I click on one specific web site it won't come up unless I got to Firefox's web browser and click on the three bars, and under my name click on sync now. Then the site comes up. The problem is I have to do this each time, on each computer. I have tried all kinds of troubleshooting to no avail. Help.

Whenever Firefox tries to sync, which is naturally happening on startup, it crashes with no error messages. I ran Firefox in safe mode by entering the command firefox -safe-mode and the same thing as before happened, but before it crashed, Firefox wrote Exiting due to channel error. Exiting due to channel error. Exiting due to channel error. Segmentation fault in the console, and then exited to the command prompt. Help!?