I would suggest setting up the bluetooth_tracker integration, adding it to the logger with the logging level of debug and seeing what you get in the logs.
Updating thread in case more people end up here after with a hope of getting the combination NUC8, ESXi, HassOS and native/other BT working. It was my highest rated search result when looking for a solution. WhimsySpoon got it working, I couldn’t.
WhimsySpoon was kind enough to supply me his exact VM configuration as I was wondering if there could be some tiny detail making the difference (thanks!). I could unfortunately not replicate his positive results despite using identical configuration. I assume it might be due to hardware/firmware differences.
I’m running a NUC8i5BEK which present the native BT USB device as 0x0aaa in ESXi. WhimsySpoon is running a NUC8i7HNK which present the native BT USB device as 0x0a2b in ESXi.
(I ended up setting up passthrough of the native BT device to a Linux VM on the same ESXi host as that works fine. BT is handled by the Linux server and passed on to HA through MQTT.)