I love the feel of the Echelon but I've tried lots of different ammo and I think it's the way I'm holding the gun.
I'm a lefty when shooting pistols and I think my thumb might be riding the slide release causing this but not entirely sure.
Purchased stiffer mag springs from Springer precision and I can feel that they're stiffer than the factory ones but the problem still exists.
Anyone have any issue like this?
Should I maybe purchase a lighter recoil spring?

Shoot it one handed making sure you aren’t riding the slide release. That will confirm if it is your grip.

Most likely it’s just your grip. You don’t need to buy anything. Just hold the gun differently if slide lock is important.

Most of my striker fired guns don’t go to slide lock because of my grip. I’ve learned to live with it.

Good idea.
I'll try this today at some point.

I am betting you are riding the slide release.  I have long thumbs and fight this on every handgun I shoot.

That's kind of what I thought.
It happened on my VP9 also, so I modified the right side slide release and it doesn't do it anymore.