Dark Lines JTech 3.8W Laser Upgrade (LaserEtch)

We have updated our Arduino to the JTech Firmware but are unable to switch back to the 0.9j firmware as described in this post: Where is the laser engraving category? - #87 by picengravertoo

Once we flash the 0.9j firmware we are unable to connect to the arduino… Any thoughts on how we can resolve this?