Hi cause-blame,
I would need to see a file, but let's do it the other way around.
Here is a file that I have tested and cached (while the c4d does not include the VDBs, that would be way too large).
CV4_2024_drs_24_RSpy_01.c4d
Please check if it renders, then cache it and check again.
The other way would be, and here I feel it would be my suggestion, to contact tech support:
https://www.maxon.net/en/support-center
Perhaps we can do both; I will look into your file.
My best wishes