I already use this machine candle and it works quite well and it's grbl and I draw with aspire 9 with openbuilds for example it doesn't give me the possibility to maneuver any axis or the probe and I get that error
seems to me you have not specified a feedrate OR there is a communication problem and the feedrate is being mangled, thus the return of 'FaN' which can be amngled version of 'NaN' for Not a Number, which happens when the USB fails to transmit the correct data, usually due to EMI. Read the EMI section of the documentation docs.openbuilds.com