Maybe not only related to 384_8 but others too and stock as well, dont know, just uptdated to last beta2 and had the trouble with it.
I changed 68U to router mode as I can allow second connection (passthrough mode with 2nd public IP from provider) on modemrouter, like a modem in bridge mode. My other router still running in AP mode on modem.
Set 68U to PPPoE, set user/pw and hard time to find VLAN setting in hidden TV page (not easy to find, never thaught it will be in TV as I only want to setup internet connection!!!).
Then I reverted back to AP mode, and could not access GUI anymore, SSH ok and clients can connect to internet, but no GUI.
After I tried a lot I remembered VLAN setting and removed it, then all was working again.
Is this a bug, I really think so?
In my understanding when changing to AP-mode the router has to forget "router"-settings and has to configure itself as AP and nothing else.
You cannot know everything what you have to change back before changing the mode to have it running correct as an AP.