Mirroring a port copies everything on one port to another port. All tags will also be copied. It wont strip the tags or somehow replace them with a new single tag.
So the destination port should not be an existing port being used for something else.
You'll need to connect this destination port up to a new different NIC on your VMWare server (should be part of a different vSwitch). The VM itself will need to be configured to use promiscuous mode in VMWare.
https://kb.vmware.com/s/article/1004099