Question about Eve Energy - CH

My Eve doesn't beep. But at 66 years old, I can't hear everything either :( Question: does it always beep, or only under load? And if only under load: with different loads or just one specific load?
If in doubt, complain as a warranty case and ask for an exchange.

I have 2 at home, and both produce a slight whistling sound.
I don't know if this is normal or a design fault.

If I listen with my ear at a distance of 20 cm in a very quiet environment, I can hear a very low whirring(?) sound. The noise is not audible at a distance of 50 cm.
All EVE Energy plugged into different sockets with different devices...