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For those struggling with phone screen turning off - I am using this app rather than changing system settings every time (android)
Here's what comes to mind first, though it might not be the best solution. https://play.google.com/store/apps/details?id=eu.aboutall.android.tools.kepscreenon I use it for watching instructional videos, and making sure the screen stays on after I pause the video.
Same here, using a Nexus 5 as a dedicated camera viewer while I'm at my desk; it was fine until around a week ago. After a bit of searching, I now use a combination of Keep Screen On and Stay Alive to keep the screen from dimming or turning off (you might be able to do it with just the first one but I haven't tried), as well as KeepRunning to automatically restart the Wyze app when it occasionally crashes.
Oh btw, if your just desperate to get this to work today like I was, and willing to spend $20 and dont have a TV which will mirror your phone, you can use the xbox AirServer app. I'm streaming my anime from the app to the tv now and it seems to work. It will send the audio through your phone, but you could use earbuds or plop a bt speaker in front of the TV like I did. Cheers.
https://airmore.com/mirror-phone-to-xbox-one.html
Ignore the first part. It wont work through the xbox ap. Used:Old LG TV, Xbox one and Samsung S9+
Edit: nvm looks like airserver DC's after like a minute.
Edit2: looks like I got it to work by combining it with the "keep screen on" app.
https://play.google.com/store/apps/details?id=eu.aboutall.android.tools.kepscreenon