Router has loud high pitched pulsing noise

[#1]

Ive had my router about a month and it makes a strange high pitched repetitive pulse noise. I can hear it over the noise of the tv especially at night. What is this? Can anyone help?

[#2]

Is it coming from the power adapter or the router itself?

[#3]

The Hub One is known for making an electrical noise whilst 5G is in use but not as loud as you describe. Sounds like a fault with either the router or power adaptor. I'd see if Plusnet will replace it for you.

[#4]

What router ie make/ model?

[#5]

Its from the router. Its a plusnet hub one. Yes im using the 5ghz band. Its not super loud but i can hear it over quiet parts of movies. It starts when noticeably when i actually use data. So ill hear it start making noise when i press play on netflix or start downloading