Temperature not shown on room overview

Hi, I have a very strange behaviour. Temperature for room Kueche/Kitchen is not shown, see below. There is a shelly HT existing and assigned to Kitchen. Same thing for Wohnzimmer/Livingroom, where everything works as usual. I have tested with new rooms, but always the same... even if I assign the HT from Livingroom to Kitchen it doesn't show up on the rooms-overview. Any thoughts?
KR Sascha