I have just updated from 3.2 to 3.3.1 on an i9-13900, 92 GB RAM, 4 TB SSD, Win11, .NET 8.0.6 machine. Now ArcGIS goes into long term (~15-20 min) freezes (circular computing indicator) every time I am adding or removing data or when I am toggling the visibility of layers in the contents; the map can still be zoomed and panned, but all menu items and tools are greyed out. This happens across all my projects, also new test projects that I created in 3.3.1 and regardless of where the data of the layers are stored. Saving the project in 3.3.1 as a new file did not help, emptying the cache and repairing the install did also not help.
What helps is uninstalling 3.3.1 and reinstalling 3.2 - but obviously this cannot be a permanent solution.
Any suggestions?