This bug has been a bane in my existence for a very long time. My own MR33 luckily does not behave this way but most MR52's and MRx6 models do show the same behavior.
Usually if you power the AP with a switch and set it up it works, then you power down the switchport and boot again, you're still good. If you go onsite and use a PoE injector on a battery then gone are the settings and you need to reset the AP, reconnect it to the cloud and set it back into survey mode.
In the very least you should be able to set channel, channel width, txpower in survey mode manually without cloud connect.
The problem usually happens at the second reboot after you configured the device. So if I have to do an APoAS I usually make sure the AP stays powered the entire day by plugging the battery in the main outlet when I take a break between walks.