(ask Marcus or me for the last 4 digits).

By the way, when terminating pinentry with "kill -TERM ...", it shuts down correctly, while CTRL-C show "gpg: signal Interrupt caught ... exiting" and a corrupt screen layout that is reset when pressing RETURN, further confirming the above diagnosis.

The problem seems to be that the CTRL-C is sent to gpg, terminating it, but pinentry keeps running and interfers with the terminal. With "ps -j" we can verify that pinentry runs in the process group and session of gpg-agent, while gpg runs in its own process group within the shell session. So, the signal rightly goes to gpg.