[BUG]: Stratify's Matrix Evaluate Expression

[Tom-Szendrey]

• Scenario: https://github.com/DARPA-ASKEM/terarium/blob/main/testing/manual/model-stratification.md
• Step: 16
• Link to the project: https://app.staging.terarium.ai/projects/f8501b9d-31ab-4551-bdef-c8e8cd3c7491/workflow/62054b38-7e08-43ef-af54-24cfd3d11bd7?operator=9a347e20-6ff4-4fae-b121-470c24bfdbf1

Describe the issue
After clicking on evaluate expression my console gets completely flooded with the following python error:

Error Message:
"Uncaught PythonError: Traceback (most recent call last):\n  File \"/lib/python311.zip/_pyodide/_base.py\", line 501, in eval_code\n    .run(globals, locals)\n     ^^^^^^^^^^^^^^^^^^^^\n  File \"/lib/python311.zip/_pyodide/_base.py\", line 339, in run\n    coroutine = eval(self.code, globals, locals)\n                ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^\n  File \"<exec>\", line 3, in <module>\nNameError: name 'undefined' is not defined\n"