Offline controller Vs LightBurn speed and power

Hi, I have an 3018 offline controller and it doesn’t perform the same as running the g-code from a pc.
I found the solution for the other issue of running a muck with comments and /r/n breaks but this is where the speed and power output is reduced by about a third. I have done a couple of test burns with the same code using the offline controller, LightBurn and LaserGRBL.
LightBurn and LaserGRBL had the same results and time but the offline controller was lighter and slower with the same g-code file.
Has anyone had this issue and have you found a solution please?

Thank you.

Jim