I have encountered a problem with emacs 28 - sometimes it skips the first button press in a very specific case. To reproduce write the following as a config file:
(kill-buffer "*scratch*")
Start emacs daemon with: emacs -Q -l this_init_file.el --daemon
Launch emacs client with: emacsclient -nw some_file.txt
Try to type some key, like 'x', and you will see 'x is undefined'
Probably I shouldn't have killed the scratch buffer in the first place, so I'm fine if it's not considered as a bug. But this used to work fine with emacs 27 and causes this strange behavior with emacs 28 which was unexpected to me.
Emacs version I use: 28.0.91