Layer shifting to right

You have to download the firmware from

Load the firmware to a USB thumb drive or send it over wifi, then start the update.bin like a print on the machine touchscreen.

Did you mean 20mm/sec?- This is really slow, and slow enough that there should be no problem even at excessive acceleration…

It only shifts in X (toolhead axis)?

Do you have the 8/20mm lead rails or the old 8mm?
If you print that slow I guess your x axis is faulty…