I checked all the connections but it still can’t get the left motor to move.https://www.youtube.com/watch?v=Q5d3FP_V2F0?version=3
I’ve seen this video before…
https://www.robotshop.com/letsmakerobots/node/30536
My suggestion is in your original thread there. I saw some other recommend a balancing trimpot as well in the shoutbox. Did you try it yet?