I'm losing my fucking mind I have made no progress all day

>"Foot.L" is child of "LowerLeg.L"
>connected to parent
>no bones called "Foot_L" or any bullshit like that, everything follows same naming scheme
>tried reimporting as "generic" then "humanoid"
>tried deleting the unity metadata entirely and reimporting from scratch
>tried adjusting the resting pose, making sure weights still work
>tried with and without "Strip bones" setting
>tried manually setting bone assignments
everything I can find about it is unhelpful
>your bones are named wrong
>they don't have the right parent
>watch this 2 hour dev stream vod from 10 years ago and buy a course