FSRM / Filegroup limit?

Hi community,

I have problems with a ransomware-detection via FSRM. I have a filegroup which contains >500 files and filetypes. If one of these files or filetypes is recognized by FSRM it should create an event. Obviously the event is not created for all extensions. for example, if I create a file with extension .oshit the event is created. If I create a file with extension .infected no event is created. Both extensions are in the filegroup. 

Is there a limitation?

Regards
Miranda