Neff induction hob tripping the RCD?

Our induction keeps tripping the RCD for random reasons. It now seems to trip the rcd nearly everytime we turn it off at the wall isolator, it all seems to work fine normally but trips when turned off.
We have carried out insulation resistance tests and found no faults.
We have also noticed that it's pulling 0.38Amps all time time what's a bit worrying for our electric bill.
Any advice appreciated for the tripping rcd