We have an open data portal based on ArcGIS Enterprise Sites 10.8.1 (https://geo.fr.ch)
All used to work fine, but recently I noticed that the attribute table is not been shown anymore, when I click on Data in the detail view of a dataset (see below). I am not sure when this changed exactly, but I am pretty sure that nothing on the data side changed.

Is this maybe a bug that was introduced with one of the ArcGIS Enterprise updates? When I click on one of the features I can see the information from the attribute table for this feature, which means that it is likely not a problem with access rights. In Portal for ArcGIS it still works as it should.
Any help would be appreciated.