I assume you did this:
Once you change the network card to vmxnet3 in the "form-view" you can't edit it again that way as it resets the network controller. On the post you reference, rootisgod says:
Caught me out a few times trying to get mine to work.
I did deploy it OK at 7.0.2 but I could not get write access to the datastore I created. Followed the guide on rootisgod with variations on the disk type but it never worked. Could create the VMFS on the allocated space but could not do anything with it - as in can't copy stuff to the datastore or deploy OVAs using it as a datastore.
No idea why. Tried ESXI within ProxMox and that was OK - but not ideal!
Shame as I don't want to run unRAID in ESXI as I only use it (ESXi) infrequently for stuff that needs prebuilt OVAs.
Tried it on a Gen8 microserver and a ML350 Gen10 so might be an HPE driver issue but was using the HPE prebundled VSphere so assume the drivers are ok.
Hope you get it to work