K40 Whisper trubble on B1 board

Hi, I’m on my third day of problem solving K40 Whisper on my Lihuiyu XB-Super-B1 (it’s not super btw),I realy need a hand.

It has a 6C6879-LASER-B1:OEM board and when using the K40 whisper the speeds and strength of the laser is way of. Cutting and engraving at 10 mm/s is aprox 3mm/s. At 100mm/s is like 20-30mm/s. Raster engraving at 100mm/s is about the same 20-30mm/s, if I type somthing outrageus like 4000mm/s the result seems to be around 30-35mm/s.

Has anybody else solve this problem?
Best regards

Do you have the LASER-B1 board selected in the general settings menu?