Campaign details missing in transition report

Hello everyone. I am experiencing an issue with a customer project where the details of the campaigns are missing from the transition report.
The reports are available in 8 other Matomo installations with the same version 5.3.1. They are only missing for this one customer.

Unfortunately, I do not have full access to the server and therefore cannot activate the PHP error log.
So my question is: has anyone else observed this and found a solution?

Thanks and keep on tracking.
Joachim