That should have been fixed in the release on the 22nd of Feb as far as I know https://world.optimizely.com/forum/developer-forum/Problems-and-bugs/Thread-Container/2022/1/cms12-cannot-delete-property-that-once-was-in-code/
"Glad" it's not just me. :) Updating EPiServer.CMS.Core to 12.4.0 fixes the problem with not being able to delete removed properties, but the sort order problem appears to be a bug still.
I also had some issues after updating to the 12.4.0 release, but they were related to the [CultureSpecific] decoration. For the specific content type property, I ended up deleting the property all together, making sure it was cleared out of the system, and re-added the property, and finally the issue went away. Might be worth trying.
It it just me, or are sort orders for content type properties no longer being updated during model synchronization?
I'm on the latest version, but changes to the Order property of a Display attribute isn't reflected in the database.
Notice how the sort order in the database is still 0, despite having been changed to 200 in code:
(This is with latest package versions at time of writing, EPiServer.Framework 12.4.0)