NavAgent not following on rebuilt NavMesh

This is for a school project and only needs to work in editor I understand there are better ways of doing this, but I'm interested in debugging this one specifically

I'm having a issue where the NavAgent won't follow the player character and I suspect it has to do with the NavMeshBuilder.BuildNavMesh();function. I've done some testing and this is what I have come up with.

Generating NavMesh, with player character and NavAgent in scene works. I can rebuild the NavMesh and it will "hang" for a second or two and then continue to work. For these examples I have the script with the NavMeshBuilder.BuildNavMesh(); turned off.

When I procedurally generate the level, with the player and NavAgent in the level, and the script with the NavMeshBuilder.BuildNavMesh(); enabled, the NavAgent dosen't follow the character - but also throws no errors, or warnings. I haven't called the BuildNavMesh yet. Once I do call the function, I can rebuild the NavMesh with no errors, or warnings.

Any help would be greatly appreciated. Let me know if I can post anything to help find the solution, thank you.