AP One AC mini keeps disconnecting

I have a Peplink AP mini plugged into a BR-1 mini, and whenever there is no client connected to the AP, it disconnects from the BR-1. It doesn’t reconnect until a client connects to the AP. It also occasionally disconnects while I am connected to it with a computer. Very annoying.

It disconnected 10 times in the last 24 hours, but since no clients were connected, some of those disconnects lasted for hours. If I had a client connected continuously, I suspect I would have even more.

The AP is running as an AP only (not in routing mode), and is running firmware 3.5.4 build 1681.

Is this normal behavior?