No problem. It sounds like it's probably a Wayland thing, maybe. Which is unfortunately not surprising. Do you have the qtwayland5 package installed by chance? You might try it, if not. You could also try:
Code:
QT_QPA_PLATFORM="wayland;xcb" sigil
which should use the xcb qt plugin if the wayland qt plugin is unavailable.
You could also try forcing the issue with:
Code:
QT_QPA_PLATFORM="xcb" sigil
if the wayland qt plugin is installed, but doesn't behave correctly RE docking widgets.