FF 148.0, Intel Mac, current 15.7.4 (Sequoia) In the middle of a browsing session I needed to consult my substantial browsing history and found it to be gone. I quit FF using the dropdown and restarted. After restarting FF the browsing history showed only that session and the TST sidebar with many tabs didn't display so I concluded FF created a new profile for startup but using my home page. I have the profile in use at the time (profile_a) and a month old backup of it. profile_a seems to have all the expected data and the bookmarks are correct. I've hacked around within Profile Groups and profiles.ini but FF refuses to use profile_a in spite of my edits, and worse is silent about it so I'm stuck and need help. Possible related issue: is TST sensitive to the number of tabs? I'm a hoarder and find TST easier to use than bookmarks so had about 700 tabs stashed in TST.