Unfortunately, this is an issue we are seeing more and more often here on the forum – The cheap Chinese motion controller’s work but they do not fully support all the Mach3 / Mach4 functions so there will always be problems with these products.
Best advice :- always buy a product which has the manufacturer’s full support and backup – you may pay more initially but you only need to buy once (many members have said this here on the forum “buy cheap, buy twice”).
Tweakie.