Yes, they were connected to the same hotel networks (when I was away this week - actually, it was a couple of different hotels in a couple of different countries).
the problem persisted . . . always around the 2 minute mark.

It’s like the PersistentKeepalive = 25 is not being respected by the GL-A1300.
Does this not mean it should send a packet every 25 seconds, and by extension restart the handshake countdown?