Load Level Instance (by Name) duplicate crashing

Hello all,

I am trying to load 2 instances of the same level, but it causes a crash.
To give an example, the following does not crash because they are not the same level:

But when I try the same code for 2 of the same level, it causes a crash, see below:

Is this a bug or am I doing something wrong? Is there a way around this other than to make 2 of the same level?

Thanks in advance everyone!