screen recording loses audio after 15 sec

If I start to record screen with the laptop mic it works fine.

If I do the same with a bluetooth headset (Plantronics Voyager / BT300M) then the audio stream goes silent after 15 seconds. 

This is only in Microsoft Stream, other apps work fine with the headset. 

I can't think why the recording would go silent after 15sec with only this type of headset and only using Stream.

I can't find any IT support for this and the device support from Plantronics has ruled out hardware issues.