Just curious on what yalls thoughts could be.

He is 12, seasoned and consistent. He has been vetted clean and just recently wanted to start dropping his outside shoulder (opposite shoulder to barrel).

I am thinking he is getting lazy on me since I’ve slacked off on my riding but i just wanted to hear a few opinions.

I'm not 100% sure what you mean??   Video?

Is horse running up the fence?   

I feel it's physically impossible to drop the outside shoulder and not fall down. 

No he’s not running up the fence or anything like that. I felt it yesterday when I was working on a few drills then wanted to breeze him through. I can feel that he drops the shoulder and it gets me a little off balance but it’s not over dramatic. It’s hard to explain it feels almost like he does a weird lead change between second and third. I’ll try to get videos I was just sitting here and thought I’d see if anyone had opinions. He may have just been being a turd yesterday.

If you think he is being lazy, be more aggressive in thinking ahead and body language about riding both his shoulders into his turns instead of his face so to speak.  Once you get his shoulders balanced coming to the turn, get him to step more up under himself with his inside leg and give you more bend through the ribcage using your inside leg.  Use your outside rein and leg to keep him from swinging his rear and pushing his outside shoulder out.  This gives you more drive from the rear end which should prevent the shoulder drop to the outside.  I feel like I know what you are talking about, but it is hard for me to explain what I do.  I tune leg yields a lot, even when trail riding.

If you feel like he is popping leads and causing it but your vet cleared him for soundness issues, try doing exercises to engage his haunches more and lead changes.  It is a yuck feeling.  Early in the season, my horse will tend to do it if she is late changing leads leaving the first to the second.  This keeps her from getting deep enough into the second because of the late lead change then she turns early and doesn't get the rear end drive off the second and will pop leads to the third, leading with her outside shoulder.  If she doesn't self correct after a few runs into the season, vets clean then I start doing some drills on her like counter bending and cantering.

Check out a dressage or might even find it on a reining forum and see if you can find some good exercises to getting control of the outside shoulder.  I know dressage riders use different exercises for when the horse wants to start riding the outside shoulder toward the rail.  My veterinarian rides dressage gave me a few exercises as well and I just apply it to the barrels. 

Are you saying that he is fading right when running to the third? I'm assuming you run to the right for the first. If he's fading off the turn or fading in your straight line go back and analyze how you're turning the second. You're probably not turning enough barrel which puts him off balance, disengages the hip, and then that will take your rib and shoulder with it. If you are turning all the way around the turn and he's fading in your straight then I'd work on him being more respective to your outside leg and rein. 

Dirt Dobber is spot on and on the same train thought as me.

It feels like he is "higher" on the left side when turning left. It’s a weird feeling lol I'm pretty sure he was wanting to try to cheat me but he knew better and it came out like that. He is a diva gelding. It’s time for me to get my butt out and get back to riding consistent.

Thank you I was curious to hear other people’s opinions and thoughts, I always love listening to other people.