Fit contributor data not showing on garmin connect web or mobile

I am the author of the "Shotgun Sports" application. The app has a couple of custom fields for the hits, misses, shots and accuracy. I just received a bug report from one of my users (Forerunner 965, Software 17.26) that the custom fields do not show up in the Lap data. I verified this with my own device (Fenix 7x with 16.20).

What I can see is:

• The Stats part of the mobile application and connect-web service show the numbers correctly for all the fields (total hits, total lost, total shots, accuracy). 
• When I go to Laps in the mobile application, I see the colums Hits, Lost, Shots correctly, but there is no data in them
• In the Connect web application I do not see any of my custom fields in the Laps-tab

The user reported that the activity they recorded about two weeks ago worked correctly and I can see that my past Shotgun Sports activities have all the data in place. 

This leads me to guess that something happened within the last weeks that broke the functionality. The app has not been updated, so maybe there is something that has changed in the firmware or API's?