I have Parallels 15 pro installed on a MacBook Pro with Catalina. I used a Thunderbolt network adapter to download the Parallels software and to install windows 10 to the virtual machine. Everything works perfectly except Windows 10 will not start if the network adapter is not plugged in. It locks up at the startup screen and locks up the MAC. It will eventually fail and the Mac will reboot. I have found that the adapter is definitely causing this because if I plug it back in (even without a ethernet cable attached) windows instantly resumes the startup and runs perfectly. Including finding the WIFI Mac network. I am looking for a solution so I don't always have to cary around the network adapter. I have even tried creating a new windows 10 VM without the adapter plugged in but the Windows 10 installer also fails to start without it plugged in. Therefore I believe it is something that Parallels is causing. I have run out of things to try.