Yeah, I throw into a net myself.
And there is a lot of times where I'll finally get what I'm going at, but just loose it because I'm not doing it on the course.
I've also had throwing on the course not stick as well. I was messing my weightshift up one night, finally got it right right and was hitting 400-450, which is rare for me. We were just throwing back to the start ot he course, not actually playing the holes.
Take everyones names and money, start the round, I could only throw 200 feet. It's not that I didn't learn it, it's that I didn't practice it on the job well enough to get it to hook for a minute.
Our minds are incredibly fickle and annoying. Such as being a form guy. Doesn't matter how much I know, my body doesn't care how much I know about a golf swing. it flops around like a fish out of water when I try and throw discs 90% of the time.
Now, if I was giving lessons for 18 holes straight, you'd probably see me shoot a -12 or a -15. Cause I have 0 issues throwing when giving lessons.
Explore the concepts into the net at home. Go to the course when nobody is there and re-draw those concepts on the tee pad a few throws at a time. That's really the best way to do it. I think that people can get to the course and throw to many off the tee and they are not giving the body a chance to think and learn.