as far I know and checking on the documentation the NFS protocol supported are 3 and 4.1
I checked on the ESXI Host Client and I can see that when you try to mount a NFS share is asking NFS version 3 or 4 ( I think they just left out the 4.1 on the Host Client) but essentially is NFS 4.1 as written on the documentation:
As @Giodomi indicated, you have the possibility to configure NFS v3 and v4.1, what is showing on the UI leads to confusion but assure that if you select 4, version 4.1 will be used.
