I have two email addresses in K9. Usually I see the common Inbox. But sometimes for example I want to switch to the sent folder (or any other). So I go to the hamburger menu. But there I see only two lines, “common acount” and "inbox ". So first I select the first to switch to one of the addresses. Then I end up in the inbox of that address. So I need to go to the hamburger menu again to finally select the send folder. Until some time ago opening the hamburger menu on the first time showed all folders of all addresses. That was much faster. At least the folder selecting menu should not close after selecting one address.
Greetings Dimitri