You probably have a bad Thunderbolt chip. No way around it besides SPI flash (which is honestly pretty easy):
https://gitlab.com/MobileAZN/lenovo-t480-thunderbolt-firmwar...
You probably have a bad Thunderbolt chip. No way around it besides SPI flash (which is honestly pretty easy):
https://gitlab.com/MobileAZN/lenovo-t480-thunderbolt-firmwar...
there's both the bad firmware issue and ports physically failing on a lot of t480s