Well it took quite a long time to resolve this and eliminate the need for a USB2 Hub.
When plugging in the Pyboard the pyboard was listed in the ESXI VM's devices as a USB device by Vendor Name and PID and was never enumerated by the VM O/S.
After applying this fix, the device is correctly listed as a "MicroPython Pyboard Virtual Comm Port in FS Mode"
But this problem
only affects VMWARE/ESXI 6.5 and looks like it is caused by USB3 Port incompatibility of some sort, but I thought I would post the solution anyway just in case anybody else should encounter this and save them some time.
SSH into the ESXI Machine and execute the following & reboot the machine.
Code: Select all
esxcli system module set -m=vmkusb -e=FALSE