There are a few possible reasons why the opposing arrows icon to make the viewing screen full size might have disappeared from your Android phone or tablet.
- The app you’re using might not support full-screen mode.
- Your device’s settings might be preventing apps from going full-screen.
- There might be a bug with your device’s software.
If you’ve tried all of the above and the opposing arrow icon is still missing, then you might need to contact your device’s manufacturer for help.