Is my controller bad? 2016 Exgo RXV Converted to Lithium

[Kyeagle3]

2016 Ezgo 48V RXT—Recently converted to Lithium. After using it a few times in the neighborhood, on one occasion, it would not go forward or reverse, but it began working a few minutes later. On other occasions, it continues to go forward at a moderate speed for a few seconds after I lift the foot, and breaking will not stop it. I replaced the accelerator switch and position sensor. I tested it and still had the same issues. When it would not move, I switched the run/tow switch, and it restarted. Any suggestions for next step?