@StephenH, I will disable guest network and report back - but everything was fine in the Nov firmware.
@arthurlien, I will send you the feedback. Thanks,
So I disabled the guest network and rebooted. The 2.4 GHz network came back. So far so good.
Previously, after a day or so of stable running, the node was losing connections with the clients intermittently (on 5 GHz). Will report back on what it does now that the guest network is disabled.