After installing ESXI on my PI 4 8GB, I can't install at VMs. When trying to install with known good ISOs, it cannot boot on any of them (even live Ubuntu ISOs) and when I select BIOS in the VM Options, it always reverts to EFI at boot. I am running the latest ESXI for ARM (build 21921575). I haven't done any other configuration on the host.
Turns out that my student ended up renaming the ISOs and put them in folders and forgot which ones were which. I was trying to install using x64 ISOs. Your reply made me check and sure enough, that was the issue.