Simple Router Bug in SigmaStudio

I've been getting a compiler error in a new project and I think I've narrowed it down to using multiple simple router blocks.

With just 1 block, the project builds but as soon as a second is added then the error appears (although the compile is still successful). The error reads 'Item has already been added..." and looks like it's a database error (screenshot attached).

The broken project is also attached.

Grateful for any information or a workaround.