Plex.tv login

Is there an issue with login into plex.tv on iPhone or iPad as far as it make you sign in almost every time? I have the newest iPhone and iPad and the newest iOS but if it’s longer than about 4 hours it makes me sign in when I go to plex.tv, not when I hit the sign in button it logs me in then I can hit launch but why does it do that all the time and it’s been happening for months

I tried to replicate your situation with my (new) iPhone SE, also on iOS 10. I could not replicate it using the app.

If you’re having this difficulty with Safari, be certain to click the ‘Remember me’ box.
The app does not sign out until you sign it out even if not used for weeks.