We had to perform the following, similar to the issue with the H700 on these pages:
C:\Dell\Drivers\1XC7Y\Windows>perccli64 /c0 set directpdmapping=off
Controller = 0
Status = Success
Description = None
Controller Properties :
=====================
Ctrl_Prop Value
Directpdmapping OFF (Requires reboot for effect)
Which gave
C:\Dell\Drivers\1XC7Y\Windows>perccli64 /c0 show directpdmapping
Controller = 0
Status = Success
Description = None
Controller Properties :
=====================
Ctrl_Prop Value
Directpdmapping OFF