Oneplus 7 pro GM1917; stuck at fastboot mode screen when flashing twrp.img in oos 11; WHY does this happen? Does anyone know?

So I had a GM1911 that didn’t do this but every time I msm into oos 11(on my gm1917) , unlock the bootloader, then attempt to flash twrp.img in fastboot, I get stuck at the fastboot mode screen. Same thing if I try it in oos 12. I haven’t tried it in oos 10 yet. Also, once the bootloader is unlocked and I upgrade to oos 12, the bootloader unlock warning is gone even though the bootloader is unlocked according to the phone (see screenshot). I ran a command fastboot oem device-info and noticed that it says false for device critical (see image). I couldn’t find a lot of Google so I asked gpt and it said:

False: This means the critical partitions are locked, which provides an additional layer of protection for those critical components, preventing them from being modified unless you explicitly unlock them.

Unlocking critical partitions typically requires additional steps beyond a standard bootloader unlock.

I know gpt can be wrong at times so I’m just mentioning this to be as thorough as possible in case someone sees this and knows why it’s saying that.

My question is, does this happen on ALL gm1917’s? And my second question is, why does it happen?

I’ve only come across a couple of instances of this on google and there was no explanation as to why it happened, if it was something the user caused, or if it was characteristic of a particular model.

I want to install nethunter which I did successfully on my old Gm1911 running oos 10, but every way of installing nethunter that I’m aware of involves temporarily booting from twrp.img.

BTW: I’ve tried asking on reddit, here, multiple telegram groups….I’m not sure what else to do to figure out why this is happening. So ANY help would be great.