Bought a Schuberth C5 and a SENA comm for it. After 2 hours on the chat line, discovered there is a Schuberth-specific Device Manager for the C5 specific named COMM the SC2) distinct from the generic SRL2, and is located on its OWN "Schiuberth" PAGE on the SENA site when you are directed to go and update the firmware on first use. This device is called the "SC2" NOT the SRL2 ....
Make sure you download THAT Device Manager called;
Works like a charm. Turns out we were chasing a solution to the SRL2 (i didn't know it had its own name "SC2". And there is an OS or Windows version of course.
There is a reference to the web page in the Quick Start Guide page 2 but it's not obvious if you aren't looking for it.
Hope that helps