extruder motor runs forwards and backwards

I have just completed building an Orballo Prusa Steel, it's my first build and the printer came with no instructions, by checking various websites and similar looking designs its now up and working.

My question is for the extruder, when I make print the first layer prints OK but then the extruder motor runs in reverse, so the filament is no longer fed into the hotend. Then the motor starts turning the correct direction but nothing prints. Is it possible the extruder is loosing its position and is reversing the motor to where it thinks it should be?

I have set the DRV8825 pots to the same position and all the other stepper motors work OK.

Could you try check out your retract settings make sure the value aren't extreme value in your slicer software, also try to check your connections too the motor extruder wire to the board, make sure it is snuggle fit

Some simple 100 mm extrusion commands would help.