Bug in the JEDI-SkyLab4?

I am trying to run an existing experiments in the JEDI-SkyLab 4.0 as
create_experiment.py $JEDI_SRC/ewok/experiments/mom6-3dvar-5deg.yaml
I had few issues related to r2d2 which has been fixed with the help of Dom.

However, I have got another error message related to ewok/src/yamltools/template.py:
File “jedi-bundle/ewok/src/yamltools/template.py”, line 128, in substitute_template_variables
full_value = full_value.replace(f’$({g})', value)
TypeError: replace() argument 2 must be str, not None

Is it a bug? Any suggestions how to overcome this?