I had the same issue and solved the problem thanks to the documentation. Solution is: if you are running a 9800-CL version, don't forget to configure the 9800 SSC Hash on the AireOS controller:config mobility group member hash peer-ip-addr 40-digit-s...
Hi bikoo!Thank you for your update! I had the exact same issue on a AP1562D running 8.10.151.0. Even a reset factory of the AP did not resolve the issue.After downgrading ME to 8.5.161.0, 5GHz is now working fine.Cheers
