Hi,
I tried the new jar file in the project that I shared with you on email, but it still doesn’t seem to solve my issue of in-game sound going mute on closing the IAB.
You can try the project I shared with you where I have just edited your sample scene to have a text box to enter a URL to be opened in IAB on button click. And I am having a background score playing on a loop in the background.
I tried the new InAppBrowser.jar, that you shared, in this project and the results are still the same, the in-game sound goes on mute on closing the browser playing a video.
Just FYI, the unity project is on my google drive here:
https://drive.google.com/drive/folders/113b4PUcR5Pq5FL2dVBdgo6vh8k6ZxH_n?usp=sharing
Hope this helps.