Thanks you very much for the advice panic mode .
Using Beyond Compare I fixed this issue by comparing the "A20.SRC", "$config.dat" and "A20.dat" files from the welder that is working to the one that's not. Then I rewrote the files of the welder that is not working to match the one that is. After a bit more work I managed to make it work.
Wanted to say a huge thank you for helping me out with this since it was a pain to deal with.
Best regards..