You're not alone... my DL32R currently has at least 3 ins/outs not working. If I take it apart and reseat the cables, it will work again for a few months. Some believe it is oxidation on the pins, others feel they don't get enough "bite" and work their way loose for people like me that moves them constantly, with 2-4 different locations a week and vibration from riding on bumpy roads, and yes, heat/cold cycles.
Glad yours was under warranty when it was figured out... hope they get it back to you quickly - it's hard to do shows without it!