I have searched some but I could not really find any posts with similar issue.
A friend of mine in Sweden got this board https://www.ebay.co.uk/itm/1PC-Durable-Mini-Rambo-1-3-Control-PCB-Board-and-LCD-Screen-Kit-3D-Printing-W2V5-/323622101360?txnId=2036161894011v
He flashed it with the firmware from V1’s Github
(My MPCNC has Ramps so Im not familiar with Rambo) and he shared that the steppers vibrates and take extra steps now and then. Same with all 4 steppers and on all channels. He tried the steppers in his Prusa printer and they works just fine.
He sent me 2 videos, one with 0.1mm steps only and another where he tries both 0.1 and 10mm.
Any suggestions for him how to troubleshoot the problem?