Squeezebox Touch can't connect to R7800

I have 2 Squeezebox Touch devices which today I tried to connect wireless to my Netgear R7800 router with r9010 installed, but I can't get them connected. They seem to get an IP address but complain about not having a DHCP server active (or something similar). As the Squeezebox Touch is a fairly old device, I already tried to reduce the bandwith to 20MHz and disable the short pre-amble.

Anyone still using Squeezeboxes wireless with OpenWrt without issues?

Use both a SB3 and a Duet/Remote with no issues, the Duet is wired though.