I discovered that my stupidity stood in the way of making it work.
I somehow forgot the basics. It works well when you plug it in to charge it for the first time. (USB cable) It will connect to your computer. You have to hold down the power button for them to start. Nothing special to do in the settings. Now they work as they should. But an annoying static noise can be heard from them. Thanks for your reply, it gave me confidence but was not necessary in my case. Sorry for that!