Player loses collision with ground when Scene is reloaded

Hello! Brand new to Unity and C#, please bear with me if I use the wrong terminology.

So I have been following Coding in Flow’s Build a 2D Platformer tutorial

and everything worked great when I went to bed last night. Today when loading up Unity, I have started encountering a new bug.

When I die to traps through collision with gameobject Die, and I RestartLevel with reloading the Scene through

SceneManager.LoadScene(SceneManager.GetActiveScene().name);

I stop having collision with the ground and fall right through. I do, however, land on the bottom inside edge of my background. I can then run and jump on the background as if it is jumpable ground.

I’m not quite sure what is causing this. I copied basically everything from the tutorial 1:1 and it worked fine last night. No idea what’s causing this issue. Maybe reloading the scene is causing something to break?

Thank you for your time.