UPDATE:

I swapped X motor driver with the Z motor driver.

I have not yet been able to reproduce the homing the wrong way issue BUT I repeated the lettering V Carve and pocket files in this order:

30 Degree v-bit
1/16 end mill and 1/8 end mill for pocket.

30 degree and 1/16 end mill were flawless. Unfortunately 1/8 end mill toolpath did not go to plan. The lettering was destroyed with what looks like horizontal fluctuation/ abnormal movement likely caused by x axis issue.

Therefore this is likely to be a bad Leadshine DMA860H microstepper driver.

I am fully aware that any electronic product can develop faults but how likely is this?

Has anyone else had driver issues before?