I just found the compatibility list here: https://www.tp-link.com/de/omada-sdn/compatibility/ It seems like the older hardware revisions are not supported (yet). Which is kind of disappointing to...

Fair point, which hardware revision are you rocking? I am on 3x EAP245_V1's. They don't seem to be supported by the 4.x Controller.

Now we just need to wait for the Linux Version