I had the same problem and solved it by replacing the Godox X2T with the Godox XPRO.
No lockups yet.
Bummer to have to buy new equipment, but not as annoying as the workflow-breaking (and embarrassing) hard lockups.
My setup, for reference:
FujiFilm X-T2
Godox X-PROF
Godox V860II-F
Tethertools USB cable
CaptureOne-Fujifilm
2x Sandisk Extreme Pro, 64MB
The only difference is the workstation. The XPRO has been used on my iMac. The issues occurred while tethering to my MacBook Pro. I will be very sad if my MacBook is the cause. ¯\_(ツ)_/¯