Hi Susi, no, you don't have to do anything. Yours are defective, just like mine. I have already received the second dongle under guarantee and it is still defective, even though I only took it out of the package. However, another dongle works perfectly.

You don't have to do anything, but I know this problem. I then plug and unplug the headphones including the adapter a few times until I hear something. It could also be that there is dust in the USB-C socket, in which case the cable doesn't come out completely.

Hello Siusi, as far as I remember, nothing needs to be done. At least with my BOSE quietcomfort 25 it worked immediately.