I just know more than BAD doctors, which you've seen quite the abundance of. I wonder if the textbooks in med school give that as the definition or something; which is really counterintuitive to me.
LH is the signal to generate more testosterone, the testes (if working properly) receive this and get to work. This triggers the aromatase response through a metabol
ic pathway, which then sends another signal to the hypothalamus (I think? It's been awhile), which then tells the pituitary to back off as enough estradiol is present. If LH is steady, but testosterone is very low; either the person has an estradiol problem (obesity linked secondary likely), or the testes are not responding, and the pituitary has been screaming for more - but similar to how insulin resistance defeats the pancreas, it is no longer pushing for additional LH.
I think I read somewhere that is a primary-secondary mix, but the root cause is from being primary hypogonadal. That's why I kind of go against the grain a little when I see low test, with good values of the pituitary hormones - as that's the "bucket" I fall into.
Is a restart attempt worth it in that case? I think that if there isn't a red flag for primary, it can't hurt - but I am often skeptical of the results. If we only had an owner's manual for the human body, things would be so much easier for sure.