Question about FreeVoice Nimbus II Mono NC

I had the same problems. In the end, I bought a Bluetooth transmitter and receiver. It worked with that. edimax BT-8500 Nano (transmitter & receiver)
But I wasn't happy with the Nimbujs II overall and bought a different pair of headphones.

I can't tell you what you are doing wrong. Switch on Bluetooth on the laptop and reconnect by pressing the silver button on the earcup/microphone side twice. Nimbus II should then be visible in the Bluetooth dialogue window. Then click on Connect.

Try to disconnect with mobile phone, then connect with laptop