Have you tried making a connection to the cloud and do a debug on the cloud environment? Furthermore debugging these actions is simpeler if you do four retrieves first. Then you can from the debug environment check the four lists and see where the problem could be.
Regards,
Ronald
It was my intention to do this indeed, but with the new teamserver, the button "enable debugger" is gone. I see only the first four options
( see https://world.mendix.com/display/howto40/Debugging )