I was doing some work and a notebook of mine got corrupted. When I restarted I used ResourceFunction instead of the pre-packed little functions, so I got a new version of the MultiwaySystem function downloaded. This code used to work:

ResourceFunction["MultiwaySystem"][
 ResourceFunction["WolframModel"][{{{0, 1}} -> {{0, 1}, {1, 2}}}], {0,
   0}, 5, "StatesGraph"]

However, now it does not. Looking at the examples again, I see the interface has changed slightly. So, if I change my example to:

ResourceFunction["MultiwaySystem"][
 "WolframModel" -> {{{0, 1}} -> {{0, 1}, {1, 2}}}, {{0, 
   0}}, 5, "StatesGraph"]

The code executes (too rapidly to actually be doing a computation) and gives a blank output. If I change it to:

ResourceFunction["MultiwaySystem"][
 "WolframModel" -> {{{0, 1}} -> {{0, 1}, {1, 2}}}, {{0, 
   0}}, 5, "CausalGraph"]

This now gives the correct output.

If I use string substitution systems, it all works fine.

Any clue what is going on?