Using my usual latest 64-bit "Build by Bill(tm)" (2.53.7b1pre from 20210202) on my Win 10 box, I observe that if you have 2 mail tabs open (like your domain's mail server and GMail), when you flip between the tabs, the mail columns displayed are the same as the tab you came *from*, which might not be troubling if they are both looking at their respective "Inbox" views... but if you were look at Sent in one, and then flip over to the other tab (which may be looking at Inbox) - the displayed columns and headers do
not change.
Easily "reset" by just selecting a different view [on that server] briefly (like Trash) and then come back to the one you are trying to see... you will have the correct columns / headers now displayed.
Mentioning this mostly in case anyone else notices it - given the things that really
need fixing, this one will probably not be too high on the list.
