The mesh network consists of 7 access points. I am getting reports of slow network performance. I look at each AP and the only one that seems to have a  problem is the root AP. On the 5 GHz band, when the channel (set on auto) is anything but 153 or 157, there  is minimal interference. On those two channels, the interference is high and that seems to be when the network performance tanks.
The 5GHz is set on auto, and it switches channels at random for some unknown reason. Could this be the cause of the poor performance? I can go into each AP and set the channel to one where there is minimal interference, but it cautions me that if I change the root AP channel, I might mess up connectivity with the other AP's.

OK, so can I change each AP one at a time with the root being the last? Suggestions?

Might be good to note that this problem arose after the software update to the controller, an OC-200. This may or may not be significant.

Up until the last several weeks, the whole network has run quite well with very few client complaints.

Art