When executing a migration, whether it is by using CloudForms, or directly importing a VM into RHV from an external provider, there should be a check in place to check the "Firmware type" on the VMware side, and set the correct "Bios Type" on the RHV side when creating the VM.
The firmware should be discovered by virt-v2v and set in RHV accordingly. We had few bugs in this area and I believe what we've faced here corresponds to what described in bz 1855001.
Due to QE capacity, we are not going to cover this issue in our automation