@Vincent-TP That would require an extra cable between modem and router, which I don't have. I can only reach the modem through the same switch that I also reach the LAN. And in fact it works, but...

On the switch I have now blocked bridging between the WAN port and the other ports, except for PPPoE. It works now. It makes no sense to me but I'm happy that it works. It really looks like a bug...

@Vincent-TP After some tinkering I think I found what causes this, although I don't know yet how it causes it. I'm suspecting I have something like spanning tree turned on but I was unable to find it...

@snoop-snoop I also have a controller, that's the problem. :) In standalone I know where the setting is but in the controller I can't find it.

@snoop-snoop How do I do that? I'm guessing you mean to set the port as a tagged port for VLAN 2 like when the router is running standalone? I can't find those options in controller mode.

I have an EAP110 and an ER605 connected with a dumb switch now directly connected and both adopted on a software controller. I have an SSID and a LAN and everything works, clients connected to this...