Actually, im using Gnome as my desktop environment and I've just realised that this is an issue when running an Xorg session. The Ubuntu instance I tested was also running Gnome on Xorg.
This doesn't appear running Gnome under a Wayland session. The home page still works for both though.
It appears the problem has disappeared. I can change the version to play on the home page and the java edition page and change the version of the a new installation, (with and without the homepage enabled)
Same problem here MCL-24220