Sodium carbonate is a strong base.
Sodium hydroxide (lye) is a STRONGER base.
Lye + copper = no-no to a greater degree.
It didn't work fine for years... more like months using the jumpers, and they got rotated ... so it took a while for the copper strands to become compromised. Once the corrosion set it, it progressed rapidly. I have learned to be more observant.
Don't know if any one else has had the issue, although I have seen some skillets that appeared copperplated... just don't know the history of how or why that occurred on those items...... could have been previously chrome plated with copper layer underneath, or... ????