I have noticed that when I am using the picture-in-picture on iOS 14, my content goes back to the beginning of the period that I was watching, even if I was watching on my TV vs. mobile device.
To reproduce. Start watching Plex on another device or your mobile device. Wait for a period of time … maybe 10 minutes or so, or longer. Then click the PIP icon at the top. The PIP window will start the content from the beginning. You can’t get to the current live programming or end.
Server Version#: 1.19.0.1399-31d8c803
Player Version#: 7.6.1