I am using tmux and I'm observing a strange behaviour. It happens from time to time that when I press "n" on my keyboard, the focus switching to tmux control and the message "Not in a mode" is displayed.
I supposed at some point I triggered something for that to happen.
It happens only in one session in one pane (number 5). Even if I close that pane, the "new pane 5" will adopt that behaviour. And if I kill all but 4 panes the behaviour is gone but returns as soon as I have 5 panes.
This is probably some setup mixup.
How can I find debug information to further investigate this?