f66 error on Miele tumble dryer

Hello, I have a Miele tumble dryer (only purchased from new 4 months ago) and it keeps saying the is a ‘F66’ error. Everything I google says that it is a ventilation error but it is a condenser tumble dryer and I clean the fluff out of the filter after every use and empty the water drawer. My only other thought is that we keep it in the garage, could this be the issue?? The only thing that seems to stop the error is turning the whole machine off at the wall, waiting 5 mins, turning it back on and trying another program. Sometimes I have to do this multiple times. The tumble dryer is pulled well away from the wall, so there is no issue there and there is nothing surrounding it, so I am very confused! If anyone has any advice it would be greatly appreciated! Thanks