I tried searching for similar, so hopefully this isn't a duplicate topic. I've noticed strange behavior lately, but to my recollection it's been happening for the last two or three releases.
I will typically have my phone locked, camera and microphone both disabled. The phone will ring, at which point the screen will light up, present the dialog for enabling the microphone. I confirm to enable the microphone, which of course I have to unlock the phone for that operation to successfully complete, at which point I would normally be presented with the phone app showing me who is calling and swipe to answer or reject.
What is happening now, is all the same except, after unlocking from confirming I want to enable the microphone, the phone app is not shown, but a notification bar with the option to answer or cancel. I can still answer the call and speak and be heard normally, but I must then actually open the phone app as if it were an application that I had dismissed to the background.
Has anyone else experienced this? Is this normal/new behavior or a new setting. I might even say this started after the update to A15 now that I think on it.