Sadly, No, boot-loader is locked. Never encountered this on both previous OP 6t's.
Hence my confusion. When I walked out of the t-Mo store with my 6t, I had No issues.
I used the wonderful mauronofios tool, to do it All with no troubles.
crash my 6t, forced to take a "9 5g" from t-Mo, and now I am regretting it.
Wondering what has changed, and by whom..? t-Mo change policies, or OnePlus ?
Actually, I've been a t-Mo customer for 16 Years ! First time I've ever had to "Ask Permission" to have my phone, or my SIM unlocked...
XDA is Great, and, yet, at the same time: XDA is very challenging.
With so many able to contribute, and the lack of external editing capacity ( unlike SO ),
it's difficult to distill the information. Okay, Great! There's a TWRP for the OnePlus 9 ! I used TWRP 3.5 and Magisk to root a Lenovo Tab M10, without any need for external input.
The Answer I'm looking for here is: Am I able to install / root / whatever my T-Mo OP 9 with TWRP ?
Does anyone have any definitive solutions ?