BoschWTA3500 starts then stops then starts then

Hi, I have a Bosch WTA3500 dryer and after I select whatever setting to start drying it starts right away but sporadically stops then starts again… then stops then starts again. I am suspecting that the door switch might be at fault (I vacummed a big lint ball out of it) And vacummed the whole thing very well… but it seems to continue to do the same start then stop then start scenario. Any ideas on what part I should troubleshoot/replace?
Thanks, CJ