Shortcuts randomly stop working
Frequently while managing my inbox and doing things like archiving (e), moving to trash (shift+3), labeling (l), and starring messages, I'll get some unexpected behavior: a keystroke (possibly fat-fingered) will cause my inbox to filter on something like unread messages or messages with attachments. After clearing the filter, keyboard shortcuts no longer work! It takes a restart of the app to get them working again.
Confirmed as an issue on version 3.5.2 (457)