Where’s my hum? I want my hum. Clearly mine’s not normal. I may return it, or demand my missing hum on a USB stick they can send me.
I jest. obvs. I don’t know whether you’ve covered this, but in use, and seated at a normal distance away, does this receiver noise interfere with your enjoyment of music and film at your normal volume levels?
If it does, it’s clearly not fit for purpose, and ought to be replaced via whatever consumer protection your country has. If it doesn’t, maybe time to ignore it, and get something playing instead?
Good luck in whatever course you decide to take.