Yeah, my experience with the UAP-AC-LITE and -LR was that it would get wonky if not rebooted every month or so. That (combined with the realization that its software load is pretty much just OpenWRT with the serial numbers filed off) caused me to dump the official firmware and switch to OpenWRT.
I was quite a lot happier after the switch, as I didn't have to hassle with UniFi and my APs stopped needing roughly-monthly reboots.
Still 100X better than the competition though. My UDM has worked wonderfully with support for dual IPs and seamless failover