My earth lead is getting really hot when welding MIG spray arc at 27volts and around 210amps. Do I need to increase the size of my earth?

Hi I’m having some issues with spray transfer practicing for my welding certification in New Zealand. I’m welding a 1G test plate which is 12mm steel with 0.9mm wire. I’m doing the first pass in short circuit then the following 3 passes in spray transfer with no issues. I flip the plate over and gri...