Alt key no longer works in tmux

[clari7744]

So this is a weird environment. I have this line in my .zshrc (Ubuntu 24.04, gnome terminal, version 1.1.0):

if [[ -z "$TMUX" && ( -n "$DISPLAY" || -n "$SSH_CLIENT" ) ]]; then; tmux new -DAs0; exit; fi

And running the editor inside tmux seems to be causing #301. Anyways, when trying to figure out when exactly that bug occurs, I discovered that the Alt key (for example Alt-f-x to quit) no longer works in a particular set of circumstances. In my default tmux created on terminal startup by .zshrc, it does work. In my regular terminal, it does work. When I comment out my auto-tmux line and open tmux manually from a regular terminal, it does not work. I believe it was working before I updated edit to v1.1.0.