Plasma cutter nozzle and magnet

Hey folks! I was using the plasma cutter today and a small bit of (plastic?) fell off the nozzle. It didn’t cut properly after that, presumably because the air flow wasn’t being directed at the melting metal. Do we have replacement nozzles, or should I order one?

Also, while I was MIG welding I left a magnet on for a full bead and the black plastic for the magnet melted. Is it best to move the magnet after making spot welds so it doesn’t melt?

The replacement is in a tackle box under the mig welder.

Tack weld with the magnet and then remove prior to welding

The pic ia for future ref for anyonw with questions about how it goes together