For many years now, I have a custom xkb layout that swaps a few keys. At the startup of KDE, a script applies this custom layout:

% cat xkb.sh
#!/bin/sh

xkbcomp -w 0 -R/usr/share/X11/xkb/ ${HOME}/etc/xkb/layout-${HOST_KEYBOARD} ${DISPLAY}

Recently, this custom layout is regularly lost. It doesn't even seem to necessarily follow any particular event. For example this morning, I had to launch my script twice, once after my laptop came out of sleep and another time because the layout had been lost while I was working on it (but not after any particular event).