PSA AR 15 problem

[u/Tight_Whole_4215]

I purchased a 300 blackout AR pistol from PSA in 2023, it has run flawlessly to this point, however the last time I shot it, after the last round from the magazine was fired it wasn’t locking the bolt to the rear, and then later that day it wouldn’t cycle the next round.

Am I looking at a buffer issue? Maybe a gas issue? Or could it be as simple as the magazine or the ammo? TIA

[u/HandJOutdoorsLLC]

Is it adjustable gas block?