MLAT in virtual machines often doesn't work correctly due to the USB having too much latency. Possible solutions will be listed here:

General portmapping, use the usb3=yes command line option or the USB3 checkbox:

• https://pve.proxmox.com/wiki/USB_physical_port_mapping
• https://manjaro.site/how-to-passthrough-usb-disk-to-a-virtual-machine-in-proxmox-6-2/

Despite that, this doesn't always work. No known solution in that case.

Issue the following command ESXi host to switch back to the legacy USB driver which can sometimes solve the issue:

esxcli system module set -m=vmkusb -e=FALSE

Changed the system chipset to ICH9
Unchecked the Hardware Clock in UTC Time box (probably doesn’t matter)
Set the USB controller to 3.0 (xHCI)

Source is this forum post: https://discussions.flightaware.com/t/mlat-on-virtualbox-success/77331