I have had an issue for a few months with the 5.xx OS and Ubiquity XR9 cards. When I was running the xr9 under 4.17 I never had any problems then in the summer I upgraded all AP’s and clients to 5.12. Unfortunately at the exact same tome 900MHZ smart meters started being install in our area. I started having an issue where the client would loses access in and out all day sometimes for ten minutes sometimes for hours at a time. I first attributed it to smart meters but then started to investigated further and discovered. that it was the xr9 5.12 combination. No settings that I changed nothing that I did would solve the issue I reverted back to 4.17 and instantly the issue went away.
So do any of the Mikrotik Experts know what was going on here???