He looked at the picture I posted online and agrees this should not happen (it should blow or carry the load safely). Marinco/Ancor did not make the fuse. He agreed it is likely a hot contact or bad fuse, asked me to send it to them using their UPS account and will send a replacement. I don't know if I'll hear back from them, but will ask for the results of their findings.

(If it was their defect at least this will provide information to them that will help avoid a repeat.)