This is mostly reiterating bug #422792 but opening a new bug for better visibility since the other one is closed.

The problem is inability to raise volume above 100% for individual application stream through the audio volume applet UI. You can see that technically it supports such feature by raising it for example through pavucontrol (see attached screenshots). And it stays at 100% for the audio device while showing 150% for the stream, so it totally can do it for a single application stream.

The are valid use cases for such feature.

For example, I'm running Cyberpunk 2077 (Wine) and it uses two audio streams, one for sound effects and one for music. When in PulseAudio prefix config, music stream for some reason has low volume. I can raise it with pavucontrol to 150% which makes it sound better. And the applet reflects it nicely. But I can't raise it through the applet itself.

Please fix it to allow doing it for the single stream through the applet UI, avoiding using pavucontrol or going through the long steps sequence like this:

click on audio volume icon > click on sandwich menu icon (More actions) > Configure audio devices > Playback Streams.