I have the same problem.
I think the problem is somewhere within the Photoplan application, or in a connection between it and the main application.
It takes main data from the photoplan itself, like quantity of modules and geometry properties (angle of the roof), but it does not transfer finished images to PVSol, so the Projekt.pdf is incorrect.
Possibly an encoding problem of some sort (please check screenshot).
My current setup is Windows 11 Home, system language is "Deutschland (Germany)"
Last year i had same issue before in versions 2022, but with other system language. Changing it to "Deutschland (Germany)" makes everything work.