Are you using CBRS and Federated as your SAS? There have been a lot of issues with them lately and we’ve found a number of our 450 3GHz/CBRS AP’s were set to incorrect channels and/or smaller channel widths. This was causing performance issues until we realized by looking at the event logs that things had changed.
As to using R22, we’ve only had one issue so far, but performance-wise, there was a small but noticeable increase in performance over R21 that we were able to actually measure due to the addition of MGPF. The performance increase was around 10-20% depending on how loaded up the AP was and MU-MIMO groupings. It resulted in more bandwidth during peak hours, higher peaks, and higher MU-MIMO frame utilization.