PC was installed back in April 2024 with UM 24.04(.0) - see this link. Since then only updated.
I recall installing Compiz last year and removed after some tests.
I was surprised to see the option "Ubuntu on Wayland" on the login screen (where you can change the desktop environment) some months ago. And yes, I was curious and started it.
It did not really work and I did not spend time in trying to find out how to make it work (I want to work with UM not with Ubuntu GNOME, therefor no need for it).