Ubuntu – Casp to Escape mapping gets reverted behind the scenes

capslockgnome-tweakskeyboardkeyboard-layout

On 20.04 LTS, pretty vanilla setup, I've successfully managed to remap caps to escape using gnome-tweaks… except it doesn't stick. Something unknown to me reverses the setting after a few hours or days.

Before I go down to putting a cron job that calls /usr/bin/setxkbmap -option "caps:swapescape" every minute — how do I figure out what's obnoxiously undoing my settings?