Soundcore q30 third pair ANC defect with same problem

Hello all,

I like your Soundcore Q30, but it is already the third pair of headphones that is defective after one year. And it’s always the same problem:

If you switch on the ANC it whistles so loudly in the right ear cup that you almost go deaf.
If you take the headphones off your head or move them a little, the whistling stops. But it starts again as soon as you move them a little.

If you switch to ‘normal mode’, so ANC off, the headphones work perfectly.

What is going on?