Tabs and bookmarks all fine. My one gripe, and it was well before v70, last Spring, Suddenly once in awhile I would click on an open tab (with others) and THAT tab would suddenly open in a new Window. (all the other tabs are OK in the old window under the new one... I have no idea how to merge them back together though. Annoys the H out of me. But it only happens if I am in a hurry, I have no idea what I am 'touching' with the pointer, but it just is weird. Since it only happens maybe once a week, I am not going to go search for the solution.
One thing.. A long while back i refreshed FireFox from the FireFox menu in FireFox. That lost all my markers. BUT, another time I did it from the FireFox website, and Darn! all my markings stayed and were still there. It may just be they fixed whatever lost all my markers. Or not??