Here are three more issues that I have noticed.
Lost my preset for the filter curve EQ. This annoyed me, so I went back to Audacity 3, only to find it had somehow deleted it there too. Now I have to recreate a new preset.
Select the S for solo, and it does not select M for mute, as it did in Audacity 3 for the track not selected as Solo. Unsure if it affects anything, but you would think it would be the same as Audacity 3.
Noise Reduction in Audacity 4 does not support Ctrl + R (Cmd+R for those who have to be different). This was normal in 3. There may be a reason for it; there may not.