Unable to set running cluster to EVC Mode Skylake

Hello communities,

currently Iam running a 12 Node Cluster with (4xGold6140 and 8xSilver 4116). Today I updated the cluster from 6.5 to 6.7 assuming i can set the "skylake" EVC Mode for further cluster expansions. We are planning to upgrade the cluster of tow new Cascadelake CPUs.

I was wondering that the vCenter said "the EVC mode cannot be set because of running VMs". Yes, I know the problems with running VMs and EVC but in my opinion i should be set the highest EVC that the CPUs in the cluster supports and in my case it should be EVC? I found the following KB-Article: VMware Knowledge Base

Does anyone know this issue? And are there other options?

thanks,

Markus