If you are running the 24.04 Xubuntu LTS release on Hyper-V (haven’t tested anywhere else) and upgrade to the latest Ubuntu mainline kernel via the normal update channel, you’re gonna have a bad time.

Lightdm crashes on reboot and you get no GUI. To fix this, can get to a terminal with CTRL-ALT-F3 and then download the latest Linux LTS kernel with all the related packages in .deb format and do sudo dpkg -i *.deb (with all those items in the same directory) and then all will be corrected.

Annoying breakage.