What should I do if I've tried all the suggestions and still cannot see the SRPM/SRCM on my MRMS?

Capture the BACnet traffic using WIRESHARK and contact an Application Engineer for help (techsupport@setra.com, 1-800-25-SETRA).  Be sure to have what each device on the trunk is, with its Device ID and MAC address, and the specific issue you are having.