I came here to see if anyone had this same issue as I'm having. I have a little more happening with this as well.
When I closed Firefox 136.0.1 yesterday, I had two windows open. One had a few pinned tabs and a main tab I was using. The other window had just the main, single tab. This morning, only the single-tab window opened up and the 2nd window (with its accompanying tabs) didn't open at all. When I opened a new 2nd window to see if I'd get my tabs back, they were gone and only the home page (which is my email) opened. I just repeated the new window to test it, and it's just opening my home page again; all other tabs are gone.
