Here some more details where you can see some logs. (blurred part are useless and/or confidential)
It happen too when i’m sharing something with the native android API.
In other words, when somthing shows up top of my app, Unity’s pause is called, but when I go back to my app, if the in app browser is still open, the end of the pause is never detected by unity.
By the way, when the browser is running, Unity considers the focus always lost for the app. Not a problem for me, but could be for others.