HW properties reports 1GB too much for VMware VM's

On Foreman 3.6.1/Katello 4.8.0.
Do not use Foreman to provision/deploy hosts, only add them to Foreman after the fact.
Just noticed that when I look in the Details tab after opening a host, the HW properties shows 1 GB more RAM then the VM actually has.
From vCenter:

Where does the extra 1GB of RAM come from?

Noticed one machine with 2vCPU and 4 GB of RAM shows:

65GB of RAM, feels a little off…

Seems to be related to VMware only. Have 100+ VM’s running in Nutanix. Here the HW properties is reported correct.