I have got some Sennheiser 4.40BT headphones. When I connect them to my laptop (Windows 10) through bluetooth, then enable the microphone, all sound that goes through the microphone gets relayed through the headphone speakers. It makes everything sound very echoey and I can hear the smallest of sounds really loudly. If I connect the headphones to my laptop through a cable I don't get this issue.

How can I stop the sound going through the microphone being relayed to the speakers?