setting - wifi - gear icon next to connected wifi - auto reconnect off?
setting - wifi - 3 dots on top right - advanced - turn on wifi automatically off?
when did it start happen? did you recently updated to android 11?
What software version are you currently running?
Have you attempted to wipe the system cache partition on the device since the recent update?
Try this and see if that helps any.
- Turn off the device.
- Press and hold the Volume Up key and the Bixby / Power key.
- When the Android logo displays, release both keys.
- An 'Installing system update' message may show briefly before the Android Recovery menu options appear.
- Press the Volume down key several times to highlight the Wipe cache partition.
- Press Bixby / Power key to select.
- Press the Volume down key to highlight Yes, then press the Bixby / Power key to select.
- When the process is complete, the Reboot system now is highlighted.
- Press the Bixby / Power key to restart the device.
Did you find a resolution to this? I am having the same issue after my S20+ updated to Android 11. All my settings are set correctly but it keeps turning my wifi on.