That’s it!
I just realized that my groups (e.g. “Alexa_Buero”) are not declared anywhere (anymore). DG_Arbeitszimmer is declared in another *.items file, but all the other groups are only used in their items declaration. Which means these groups do not really exist. Maybe the picker is trying to show the items in one of these groups but as the group does not exist, non of the item is shown.
…
Correct. I’ve just tried to remove all groups from an item and it is showing up in the picker ungrouped. If I declare the group itself, all the other items are available too (with this re-defined group).
So maybe as an idea: currently all items are shown in the picker when they are in an available group or fully ungrouped. Maybe we should also show them when they are in groups, which are not really available?