GraphToolkit GraphMotion.Play throws ArgumentException for nodes within subgraphs

Reproduction steps:

1. Open the “gtkdebugrepro.zip“ project
2. Open the “Assets/Samples/Samples for the Graph Toolkit Module/0.6.6-exp.1/VisualNovelDirector Sample/Assets/VisualNovelScene.unity”
3. Open the “My Visual Novel Graph” graph
4. Enter Play Mode
5. Observe the Console

Actual result: “ArgumentException:Invalid node ID" is thrown
Expected result: No exceptions thrown, the game works, debug visualization works in subgraphs.

Reproducible in: 6000.6.5f1, 6000.7.0b4, 7000.0.0a7
Could not test in: 6000.0.84f1, 6000.3.26f1 (Compilation errors)

Reproduced on: Windows 11
Not reproduced on: No other environment tested

Note: You can verify that the game works when debug visualizer is turned off by commenting out the first line of VisualNovelDirector.cs (“#define DEBUG_VISUALIZE”)