As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
CREW BEGAN DESCENT FROM FL230 AND AT AROUND FL200 HAD AN ACS LOW INFLOW CAS AND SAW THE CABIN ALTITUDE RISING. REQUESTED AN EMERGENCY DESCENT TO 10000 AND RESET THE ACS SYSTEM. ACS CAME BACK ONLINE NORMALLY AFTER THE DESCENT AND LANDING WAS UNEVENTFUL.