This is a bug report for Android 5 and it hasn’t been reported since, so I doubt there is any info there that helps you.
If you believe you encounter a bug involving the proximity sensor then report it in the bugtracker.
According to this post it has been reported for Android 6 here, where you can see it once the bugtracker is up again.
I’ll answer the rest in your other topic. In the future please don’t post the same stuff in more than one topic.