Repeater with OpenWRT as VLAN Client?

Hi all,
I have OpenWRT 21.02. running on a FritzRepeater 3000 which is configured as Access Point. It is connected to a router/firewall (IPfire) via LAN. The router provides access to the LAN (home network) and a tagged VLAN (network for guests) via the same LAN cable. DHCP is running on the router.
I have configured a device eth0 and a bridge connected to Wifi interface with SSID "home" providing access to the LAN (home network). It works without problems.
Additionally I want to provide access to the VLAN (guest network ). Therefore I configured a device eth0.66 (Type "VLAN 802.1q") and a bridge connected to a wifi interface with a SSID "guest".
the Wifi interfaces are up, but for some reason I cant connect to the guest wifi.

In principle, is the way I configured the VLAN the "correct" way or did I missed something?

Thanks for any hints/help.
Kind Regards