Is My Regulator Busted?

I've been trying to get my dual regulator dialed in. The one on the left works great, I can set it to where I want easily with no problems. The one on the right is giving me all sorts of problems. I turn off the gas, use the valve to release the gas in the gauge. I have the screw completely loose. I turn on the gas, go to turning the screw clockwise, as soon as there's tension it goes straight up to 15 psi, I can't get it any lower. Is it broken?

The second issue is the cardboard in both my gauges are folded, so I can't even see if it's going up past 15 psi. Which isn't really a big issue for me, I want to use the set and forget method, so I'll never really need to go above 12 or so psi (I think!). I thought about taking it apart and trying to fix the issue myself, but if the regulator's broken, then I'll need to return it anyway.

Look for a weep hole on the regulator. Cover it with your finger...does the needle go up?

You've probably got to rebuild the regulator. What happens is...the valve seat leaks...so even though you didn't screw in the adjustment screw...it's letting gas past anyway. Then the diaphram is screwing up too...it's holding the pressure until 15 psi to release it...and it's coming out the weep hole.

If you're weep hole isn't letting gas off...then I'd replace the gauges to start with and trouble shoot from there.

If you suspect that there's crud inside the regulator...it wouldn't hurt to pull it apart (note the position of everything) clean the valve seat/valve and any other gunk...and reassemble.

If it's new enough to return, do so. Sounds like you have multiple flaws.