Hello MatteoB729! Thanks for posting and welcome to the Community.
I am sorry to hear you are having difficulty, but am happy to assist. When you say "blocks audio output" does that mean that the audio drops or are you receiving a notification that the output is blocked?
It is unlikely that two separate headphones had the exact same fault so it may be that something else from the phone side is happening. Does this happen with multiple devices? What about different sources/apps?
Let us know so we can help resolve the issue!
Greg - Community Support
Jun 15, 2018
@MatteoB729 I do not work for Bose but as you probably can guess - it is not a universal problem.
What you want to tell Bose here is:
1. Are you playing audio through an app locally on your phone? If so, which app. Do other local audio playing apps have the same issue?
2. Are you streaming audio and if so through which services - youtube, spotify, etc. Is the streaming associated with video or just audio?
3. If you stream, is it via 4G/LTE, 5G, or Wifi?
You'll want to use the above to provide guidance on whether it is happening with just some things on your phone or everything associated with your phone.
Thank you for checking the different media sources. As it appears to not change when using these, have you tried pairing the Headphones to another device at all to see if it still has the slight audio delay?
Leon_C - Community Support
Feb 28, 2019
I have a similar problem with samsung s8+, computer bluetooth and bose qc 35 II
I am playing spotify through computer, whenever s8+ tries to make a sound, the qc35 ii drops out for a second (but doesnt make any sound)
Thanks for reaching out to us!
Does this issue occur when you pause the music on the first device, then play from the second, or only when you try and play when the system is already playing?
Furthermore, is this just for notifications, or is this for all audio?
Please get back to us!
Thank you for testing that out for me.
As the issue appears to be directly a compatibility issue between the QC35 II headphones and your Samsung Galaxy S9+, I've done a little bit of research and found that it could be a Bluetooth version issue. Currently the QC35 II has a Bluetooth version of 4.1 where as the Galazy S9+ has a Bluetooth version of 5.0.
As they run slightly different versions of Bluetooth, they can still connect and you can play audio, however this could be the reason as to why you are encountering this audio delay.