"Scenes in build" disappears on play

Preface

This is on Unity 2018.3.13f1 Personal

Before: 137010-before.jpg
After: 137011-after.jpg

What happened

Whenever I add an open scene and save both the project and the scene, it will work while switching scenes. Once you press play, all of the scenes will immediately show as ‘deleted’ in the Build Settings and will not save the order or the file names.

Things i’ve tried

1 - Uninstalling Unity and reinstalling

2 - Restarting Unity

3 - Re-importing the project

4 - Deleting the ‘Library’ and ‘Temp’ folders

5 - Resetting packages to default under ‘Help’ tab.

I honestly don’t know what i’m doing wrong.

Alright folks, this is a really stupid/simple answer. If you get this problem and you are using
“TerraLand”, an asset for terrain building, DO NOT press ‘Accept’ after you press play. This will overwrite the project’s build settings and delete the hierarchy of scenes therein. Hope this helps!

Please enjoy my badly photoshopped example: