[OnePlus 10 Pro] beatbreakee:
OK... with the TMOBILE 10T, they designed the bootloader to be actually locked and hidden in a unassigned partition on the device.... A COPY of the bootloader is then placed into USERSPACE, and given USER level access via FastbootD... which is a neutered Fastboot that is closer to plain ol recovery... it has a FEW more functions... but all FLASHING, OEM, UNLOCKING commands are removed from the binary, and replaced with a notice that "this action cannot be performed in the current default space" ... any method for normally loading Fastboot including dongles such as Hydra tool, or even another tool which forces the device to boot from otg/sdcard cannot access FASTBOOT MODE. The device has an INIT script hard coded to the reboot bootloader commands, which sends a "boot continue" argument directly triggered by the bootloader command, so your device NEVER even stops to acknowledge the Fastboot Mode... its rebooting before your cable, pc, or tool ever has a change to register it! OPPO created a special tool called "In Depth Testing" tool, which essentially makes you 1st acknowledge that by using the app to make the request, you are directly confirming that Oneplus/OPPO has complete discretion as to any claims for warranty repair, if it is Software related. Once you tap request, it makes you tick off another check box with more warnings, and then hit submit..... a formal request is then processed thru some server in india, where they review the request and ultimately approve/deny it within about an hour. If you live OUTSIDE of the region where the app is originating, or your device model is a mismatch AT ALL of the model they made it for, you cant even submit... the app cancels your request, and nothing gets sent.... im currently working on figuring that out... but thats stuff beyond my range... Im hardware... firmware..... and some linux/microsoft/mac programming.... Android sdk is NOT my forte, cuz too much of it is bastardized linux, and in a way its like trying to get a PURE DNA sample, from your 8th cousin, on your step brothers, half-mother's side! ... I know linux... Debian, Kali, Ubuntu ... Android is some of this... a bit of that.... part of the other.... some stuff borrowed from emergency linux... a whole lot of Elementary... some Pacman, Gentoo, and source .... wrapped together and governed by the most semi recent Linux Kernel in use. Imaging being Dad = Kernel .... with all those kids (each part of a build) ... living under 1 roof, (Android OS)... then mutated for every device manufacturer who wants a flavor, but not the original! YEESH!

In the beginning i was able to get to FASTBOOT! .. straight white text, red highlight on selection, and a green top mode... real fastboot.... never even saw fastbootd ... but i cannot access it via keys... only thru ADB REBOOT BOOTLOADER

.... now i dont have that access, cuz i cant get the android setup, to complete, and unlock the Build Number, tap recognition, to turn on developer options. If i can get that done, then i will be fine, cuz i will fastboot unlock the bootloader, and flash the partitions individually. If i can get fastboot back in my reach, then i will totally region swap and unlock... and if that somehow breaks, i will make sure i root 1st and put the ADB KEYS in the correct spot so my recovery mode is authorized.... thus i can always access fastboot....