hictop prusa i3 raises nozzle on 0.3 increments, why?

I had a problem at first, that after calibrating all to ok setting and nozzle homing right but when pushed print, it raised Z to 0.3 at start.
With slicer 'I was able to put in z-offset to -0.3 but when it started to print, it raised to 0.1
0.1 seemed to be ok for first layer but then it raised to 0.4 so it increased it by 0.3 and all went to hell.

What is wrong? some setting or something on firmware but what?
I have newest marlin firmware installed and configged for this model.
my e steps are 2560 i have 8mm rods with 1.25 rise so I think I calculated that right?
or well I think it has 1.25 rise since so many others on same kit too has same specs.

only question is that what driver does mpx-3 use? i used the 1/16 polulu but can it be different? where can i find it out.

Remember that the Slicer program tells the Printer what to do, this could be a result of incorrectly slicing the Model.
What are you using for a slicer.

Problem was that e-steps were totally wrong.
I have T-ballscrews and steps are 400
Hictop sellers provided me with nonstop wrong info or actually their retailer. They did not even know what model this was...

Apparently you have the same as my Hictop 3DP12.
8mm T8X8 Trapesoidal Lead Screw, which has a 8mm rise for a single turn

My Hictop 3DP11 has a 8mm x 1.25 all thread which has a 1.25mm rise for a single turn, a factory "junky" lead screw.

This lead screw will be replaced with a 8mm T8X2 Trapesoidal Lead Screw , which has a 2mm rise for a single turn

I Calculate all with a RepRap Calculator " here "