You don’t do a nice steady squeeze, you jerk that trigger back and BANG…your round impacts and not where you want it to.
This is VERY common, but something that should be trained.
Something I do, when I’m getting warmed up, is I talked to myself (don’t worry, I don’t answer myself).
I tell myself, “slow pull, slow pull, slow pull” until that first round goes off. This helps slow me down and calm the excitement of going live on the line.