Hello there...

After updating my 7740 to latest BIOS 1.20.2 the TB3 port is not working properly. I had a WD19T docking (with 240W power supply) connected, which did not charge the 7740 anymore. Also, no USB stick or connected LAN was working. First thing I thought is that docking is gone to nirvana, so I replaced it by a brand new one. Nothing changed... Also my external Samsung X5 connected directly to TB3 port was not recognized any longer.

I finally downgraded the BIOS 1.20.2 to 1.18.1 and guess what...? Yep, everything is working fine again! 

Thanks to them Dell BIOS programmers (which are not really doing a good job... remember the UHD issues last year) I bought another WD19T for just nothing...

Cheers!