Please check out OS 8.6.6 which should solve S/PDIF glitches with some sampling rates on PROFILER Stage models as well as some other issues.
This OS is currently available as public beta. Rig Manager will recommend it, if "Beta" is selected in its Preferences. It can also be downloaded for USB flash drive upgrade here:
I can confirm that with 8.6.6 it's working fine at 48khz now. Thank you !!!