Just posting this here for anyone who may be Googling for answers or anyone on the forum that has noticed connection issues with Macs/iOS devices getting disconnected on Unifi APs running the latest firmware (4.0.80). Rollback the firmware to 4.0.69 and your problems will disappear.
I’ve had no issues for years with my AP-AC-PRO and for some reason this latest update clashes hard with Apple’s wireless cards. I updated firmware just over a week ago and it’s been a week of issues. In the controller dashboard I’m seeing 336 WPA Authentication/Timeout Failures for the last 7 days, compared to 352 looking at the entire last 30 days.
So if you’re having the same issues or clients are reporting it, that’s the first place I’d start.
And for those, like me, who have never needed to rollback firmware before - it’s really easy. Select the AP in the controller, click on the ‘config’ tab -> ‘manage device’ section -> ‘custom upgrade’ - paste in the correct previous firmware download link from the Ubiquiti downloads site and hit the upgrade button.