Problem with CO2 regulator

This past weekend I had to crank up the pressure to around 30 PSI to get a stubborn keg to seal.
This was a first for me since I have always been able to get a seal at 10 PSI.
Anyway, after the keg sealed, I tried to turn the pressure down but I can not return the adjusting screw back to its original setting.
I was able to back it off to a 20 PSI setting but it is stuck there and and I can not get it to move in or out.
Any suggestions?

First, is the nut on the screw tight up against the housing? Back it off and you should be able to adjust.
Failing that - give it a shot of WD40.

The locknut is fully backed off but that should not affect the CCW movement of the adjusting screw.
As I mentioned earlier, I almost never have to move the adjustment screw. And then its only to make a 1-2 pound +/- adustment.
When I increased the pressure the screw moved OK.
I’ll try the WD-40 thing. Can’t hurt.

Try letting the pressure off by turning off the valve & releasing the pressure. Mine doesn’t stick but it is much easier to turn out w/o pressure on it.  Cheers!!!

Tried that last night. No luck.

Over the weekend, I dribbled a little WD-40 on the adjusting screw, worked in back and forth for a couple of minutes and was able to free it up. (Not sure why I didn’t think of the WD-40 since I’m a duct tape and WD-40 kind of guy.)
The screw threads appeared to be slightly damaged but I was able to move the screw throught its entire range without any issue.
Thanks for the help.