I have had this happened to me before, I think it has something to do with Android closing the app because of needing more RAM, hence you go back to FF and find out a blank page or sometimes it is not even the correct tab lol, refreshing it won't fix it thus you'd need to manually close, or force close the app to get it in a working state.

Also, I haven't checked on mobile, but the PS Store website just crashes Firefox entirely in macOS lol, those kind of annoyances weren't present in Chromium based browsers, and I can see this being a huge downside for most people, for me it is worth it because FF is so damn cool.