Thanks, I'll give it a try and see how it goes.
I know it has to be a switch/hardware thing, as I have the exact same config VMware wise at work for our massive vSAN on vxRail clusters and the counters flatline at 0% day in, day out!
(The only difference is Dell server kit vs the HPE I have, and Cisco network gear versus my Dell)
Surely there has to be a logical solution, or some simple setting we've forgotten to configure on the switches?