ASUS UX303U - Discord mutes all other applications, BT headphones

Hello everyone,
I come to you with my problem, namely when I have Sennheiser HD 4.40 BT headphones connected, it all plays nicely, but when I start a conversation on Discord I can't hear any other application. With the settings I have in the screenshots below, I can't hear other apps while chatting on Discord.
In the picture with the playback settings, if I change the Headset to the default device, I can hear both the conversation and the applications, but the sound quality is significantly deteriorated compared to the sound played on the headphones (only then I cannot hear other applications as I speak via Discord).
If anything else is needed, I will add it.
Thank you in advance for your help.

I have the opposite problem. I want to reach the state you want to get rid of because I don't like it when the game drowns out people on Discord, but I think I can help you with this problem. Unfortunately, I was unable to achieve this effect from the windows settings. Because even though I set it to mute by 80%, nothing has changed:

Btw. these options are available in the tab communication visible in one of your screenshots
I also combined all the ways with the exclusive mode (as shown in one of your screenshots). I set up default playback device that it was also default communication device and all these windows settings did not give any expected results. But I suspect that it will help you, so make sure that these headphones are at the same time default device and default communication device (because according to this screen I can see that the headset is currently your communication device). So you right-click on these headphones and choose to have them too default communication device

But I also noticed that Discord itself has an option that mutes other applications and it only helped me

In your case, you move this slider to 0%, which is all the way to the left and thus Discord does not mute other applications
Well, for example, I still use Team Speak and I would like to have it there too. That is why I connect to the topic and ask for help on how to do everything from the Windows level, so that no matter what communicator is used, this mute really works (I also have Win 10 64bit) and it was not supposed to work, but only in theory - because somewhere there is one option for this corresponds, but unfortunately in practice it is often not the case that only in 1 place we will change something obvious and hops already works - there are many dependent options and situations (because each of us connects to a computer differently, has a different computer and different settings, not infrequently invisible spontaneous system errors), which contribute to the fact that reaching a solution to the problem is almost a miracle. Why does it work for you right away and I have to work hard for it, and it will have a poor effect so that it calms down. How the f ... is it?

Hey, I had the same problem with my BOSE headphones. It turned out that the headphones have two devices under them in software, a headset and just headphones. When Discord connects through the headset, you can use the microphone from the headphones, but you can't hear anything other than Discord, unless you change the default output device in Windows from headphones to just the headset. Unfortunately, everything except the conversation sounds hopeless on it, it somehow seems to bypass the sound card and is more rt, which is great in conversations, but not for listening to, for example, music. An alternative solution is to use an external microphone from e.g. a laptop and set the output device to headphones in the system and in Discord. Then everything sounds better, but unfortunately you have to use an external microphone