Hi Dusan
You are correct, those versions of ESXi are supported with that version of v2110 software.
What is not supported is updating the virtual hardware, updating the virtual hardware is analogous to replacing an entire PC hardware system and expecting pre-installed software to support it the new configuration.
So if you are on ESXi 6.5 and hardware 8 and have issues, then please open a case with GTAC and we will look at it.
My understanding is that now you have rolled back to virtual hardware 8 and are on ESXi 6.5, everything is working, please correct me if I'm wrong.
-Gareth