Why do some PCPs prescribe ADHD medications and other PCPs won't?

My son (11) and I both have ADHD. We recently moved back to our home state, and my PCP here will not prescribe ADHD medications (thankfully I have a great psychiatrist now, but we had different insurance at the time we moved back which made it difficult to find one at all). My son's ped will prescribe him his needed meds, but it's clear his doctor has little experience with children with ADHD. He puts more restrictions on us picking up his medications than I ever experienced with the doctor in our previous state, and compared to the first pediatrician we saw in the same town in our home state.

It really feels like there's this huge stigma and mistrust towards my son and myself, although we've done nothing to earn it. This ped won't let us pick up my son's meds except on the day after he runs out, and then say "it's the 'system' that does that because it's a controlled substance" and that it's not a specific instruction from the doctor, even though I know they “system” part is a lie. I know it’s controlled, I get that. However, our pharmacist has told us it's a specific note from the doctor saying that it cannot be filled until XX date. I also know it's because we were able to fill his prescription earlier with the previous doctor.

Also, I can fill mine within a week of running out. It has nothing to do with us using our medication faster than we should. Simply convenience, and being able to pick up meds when the pharmacy is open, while having two, full time jobs and parenting. But they'll say "you picked it up on the 17th last month, so you can't pick it up until the 17th this month." I have had insurance stop us from picking it up sooner than 5 or 7 days before the 30 day mark. Us picking it up "early" has to do with convenience, and being able to continue medication without a gap in care. I'm so frustrated with this. I really miss our amazing doctor in our other state. She was so understanding, took her time with us and treated my son and I like people rather than suspected drug abusers.