Empty monitor file while preprocessing observations

Summary

I'm trying to follow the steps in the online tutorial for developers, 6.2.4. Pre-process observations to fit in model realm, and the produced monitor file is empty.

Steps to reproduce

Run the attached yml file.

What is the current bug behavior?

The variables are there, but they all have dimension sizes of 0.

What is the expected correct behavior?

Filled with the actual values produced in tutorial, 6.2.3 Generate a monitor file compatible with the CIF/

Relevant logs and/or screenshots

yml file: jvp_obsvec.yml
log file: jvp_obsvec.log