Useful links for the part and an engineer should you need one are below,
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A step by step guide on why your Hotpoint or Indesit dryer starts buzzing when the start button is pressed
Find your part here
https://appliancesparesrus.com/tumble-dryer-door-probes/
Hearing a different buzzing noise? have a look at this video. https://youtu.be/DZy9xjHGq38
The strike pin is usually dislodged due to hanging laundry on the door, or it sometimes breaks at the end. But the issue is that it is not making contact with the microswitch.