I’m using the Android app.
I’m losing screen real estate to a vertical tab on the left-hand side of my screen (“stacked tabs” / sliding tabs / Andy Matuschak tabs) that I can’t seem to get rid off:
Swipe down from the top (the default gesture to trigger the command palette), type toggle stacked tabs, tap, and that will turn it off. You should also be able to get away with typing sta in the command palette.