High frequency noise coming from External HDD

Hello. About 6 weeks ago I bought a brandnew Western Digital Elements 10TB External HDD. There were no issues whatsoever and I was quite happy with the product. However, some days ago after turning off my PC, I noticed a high frequency beeping noise. I searched my room to determine where it’s coming from, and I realized it’s the new WD HDD. I switched the adapter because last time I heard such a noise it was the faulty adapter of my monitor, but despite switching the adapter the noise stayed until I completely unplugged the HDD from electricty, so I concluded it’s the External HDD itself omitting that noise.
Does this mean it’s faulty, or is this an interference from other devices that I hear? I googled some and all I found were informations about clicking/buzzing/whatever, which isn’t the case.
I have several other External HDDs from other brands and I never noticed such a noise, it also wasn’t there during the first weeks after purchase.

I already have many files on the HDD, so switching it out wouldn’t be easy since I have no other place to store them, so I want to make sure if it’s actually broken or if it’s a noise I need to live with, that’s maybe caused by the HDD not being “grounded” (don’t know if it’s the correct word, not a native English speaker). If so, why would it start after weeks?

It could be the noise from the power adapter. If that is the case or the noise from the hard drive. You can get a replacement from Western Digital

I switched the adapter because last time I heard such a noise it was the faulty adapter of my monitor, but despite switching the adapter the noise stayed until I completely unplugged the HDD from electricty, so I concluded it’s the External HDD itself omitting that noise.
It is not the adapter. I would like some insight on this. So my 6 weeks old HDD is broken because it’s making that noise?