Tag auch,
gleiche Problematik auf meiner Seite, geholfen hat mir die folgende Lösung:
So the real problem here lies in lack of 802.1x (VLAN) support in older firmwares. To future readers: go tag the port in your switch with a single VLAN, rather than allow "All" VLANs
https://www.reddit.com/r/tradfri/comments/ruixzb/psa_trådfri_gateway_and_unifi_equipment/