If its firing when you aint touching the trigger, you got issues. If its firing after a couple of trigger pulls your settings are wrong.
Dont quote me on this, but its either setting 3, or 4 on the board, and set it to 1 for semi. Should tell you in the manual anyways.
In the PMR manual, there is only 3 firing modes listed but theres actually 4. The fourth being full auto. Your SLG may be the same.