The brave browser in ubuntu and fedora with plasma, separates the icons of the PWA applications and handles them as independent applications, as I can do this in Manjaro.
Google Chrome and Microsoft-edge if they do it.
Okay, so what’s the issue? 
Isn’t the issue using Brave (as well as Chrome or Edge) ?
Brave is absolute bloatware.
If you want to properly manage PWA, install them with Bauh
As for browsers, you’ll be efficient with Firefox and Epiphany (Gnome browser)
Epiphany’s integration with PWAs is very poor, especially with applications with the use of DRM such as netflix which does not work and firefox does not offer PWA integration, for now I partially solve it using webapp-manager-manjaro, but it does not overcome the integration when done natively.
Thank you.
Where from do you infer using Firefox (which dropped SSB support) or Epiphany as PWA support ???