I recently setup HA using Virtualbox before the 12th (2024.1.3 release date) and it worked perfectly - the UI was responsive, set up some integrations and dashboards etc. Then on the 12th I attempted a brand new install which was after the 2024.1.3 release (the new install only starts up after it’s performed an automatic update - I can see this by running ha job info, showing an update running). I’ve tried both Virtualbox and KVM, but either way the experience is far worse. The UI is dead slow - even switching between menus for Home, Maps, Energy, Settings takes several seconds. Clicking any menu item is similarly slow, loading addons from the store takes dozens of seconds.
Keep in mind this is a brand new installation and tried it on a wired and wifi connection. I have done nothing at all to the setup.