I feel your pain. I had to turn off the dual 5GHz radios because of similar issues on the AP650. I know, it’s 2020 and we’re still being led to use 2.4GHz because of these situations.
However, I am using DFS and have ACSP enabled as well. Power on the 2.4GHz radio is 1 dBm and the 5GHz radios are at 2 dBm w/ band steering enabled. The only exceptions are in larger areas (gyms, cafetoriums, libraries, etc.) These areas may have dual 5GHz enabled along with automatic power adjustment.
With AP’s in every classroom, using the automatic power adjustment isn’t nearly as effective as it should. You should be able to fine-tune your auto power levels however you see fit; not min 2 dBm and max starting at 10 dBm. Like what you are seeing, radios using the same channel right next to each other, yet they won’t change the channel. However, DCS works well for us in the evenings but really didn’t help with the dual 5GHz radios from using the same channels. I would still find high CCI, CRC, and duplicate channels next to each other. Hence, needing to turn on the 2.4GHz band and the intended by design limitations with turning a radio off .
As for MU-MIMO, I haven’t had one GTAC engineer recommend enabling it . I really want to use it, along with so many other important features with ours AP’s, but enabling certain features and perameters have broken user connectivity one too many times.
thank you for sharing that link; I hope it does correct the issue.