PS5 making some kind of coil whine or buzzing sound during intense gameplay in certain games

So I got my PS5 about a month and a half ago and everything has been great till the last couple of weeks. It’s slowly been getting a little worse here and there. Sometimes noticeable, sometimes not. For example, when I play Crucible in Destiny 2 it starts making a slight buzzing noise or coil whine. The frequency of the sound sometimes fades in and out from barely noticeable to noticeable. I’m super scared and don’t know what to do. I bought it new off Craigslist and the proof of purchase I have is the Order Details and Summary, not the damn receipt that Sony wants. I don’t know whether Sony will honor my warranty if I send it off with that as proof of purchase. So, what are some of my options here? Is it worth it to buy the right screwdriver and remove the fan and check it out? Some video on YouTube shows a dude with a similar problem and he fixed it by putting rubber rings on the screws for the fan mounting. It’s hard for me to diagnose actually what it is and I am willing to record it later tonight when I get home and show you guys exactly so we can better work out my options.

Thank you very much!

EDIT: Also, it doesn’t really happen whenever I play something less intense like Monster Hunter World. Weird…