well when I open the settings first time after computer start, it seems to close. but if it happens always on your side.
but maybe you can reinstall settings app? maybe it works the same way as reinstalling Store app through powershell as admin with Add-AppxPackage -register "C:\Windows\ImmersiveControlPanel\AppxManifest.xml" -DisableDevelopmentMode
I tested this even if settings was working fine here, everything still works haha. but maybe you can try it and see if it fix any problem
also about the Ethernet, maybe it's a driver problem? that's the only thing that could affect anything especially if it's about Ethernet. is your school Ethernet working good on a Windows 8/7/vista/xp computer?