You can't claim its a bug in
ESXi, perhaps a configuration mistake probably
ESXi works good with about every
OS I have tested.
Specially Microsoft/Mikrotik/Linux ,
I have deployed may scenarios with Mikrotik / Squid Proxy and Radius Manager in one Server with
ESXi Virtualization technology and all of them works great with lots of pwer saving, easy management, easy backup and restore using
VEEAM. once all machines are configured properly, create there backup with veeam or any other tool and you will sleep better in night, in case of any disaster, just restore the last working image of that particular guest.