We need more info to go on to offer you any help.It could be a number of things why it's shooting low. Chrono the gun first thing when you shoot it, while its going through the phase of shooting low. Keep chronoing it untill it groups where it normally does. It could be the reg playing up.
Also leave it a few hours then chrono it again. If first few shots read high then return to a consistent state the reg is leaking.To check it properly it needs to be put on a reg checker.
Let your shooting do the talking.
It's not the aim and release that decided the shot, it's the preparations.