New switch Item added from Homematic Binding does not show switch slider in sitemap

I added another Homematic switch Thing HmIP-PCBS to my openHAB via admin gui, created a coresponding item via .items file as I had done multiple times in the past and added this item in default.sitemap. But this time the item does not display the switch slider, only the state is shown:

I removed item and thing from openHAB, removed the HmIP-PCBS from Homermatic with reset to defaults, recreated it in both worlds but the same result again. No switch slider.

I have multiple switches from same type in Homematic and corresponding things and items in openHAB, all of them created in the same way, all of them have switch slider(s):

My system: openHAB 3.4.4 running on Debian GNU/Linux 11 (bullseye) fully patched, RaspberryMatic ver., 168 things, 846 items.

Any idea what’s going wrong?