Do you have the steps you took for losing the mud coin?
Not really. Something about misclicking and dropping the silver coin instead of inspecting it and then trying to pick it up. But when picking it back up I got another mud coin. Then when I tried to drop it I got another mud coin in the world but it stayed in my inventory. Then it got duplicated, now I can duplicate it infinitly. Thats all I remember, hope this helps