Highlighted content Webpart - Managed Property Filter Broken?

Hi all

I'm currently trying to configure the Highlighted Content webpart, but "Find a managed Property" Filter seems to be broken.

Earlier, i have configured the same webpart already on the same page successfully. Now, when adding another Highlighted Content Webpart to the same page, i'm not able anymore to filter by the managed property, the dropdown just remains inactive.

Regardless what i type into the find textbox, the dropdown never gets activated.

I even realized that when changing the find-Text in the "old" Webpart, the choices do not change as well, contentclass remains there. Hence there seems to be something broken with the update of the dropdown?

I tested on 2 different tenants with IE, Chrome & Firefox, all the same issue.

Anyone else facing this issue?

Thx

Martin