I am working on a model that has on-grid power as one fuel and off-grid electricity as another, following the guidance from this thread. Both off-grid and on-grid power generation are separate modules in the transformation trees, with their own processes. I also have separate demand for on-grid and off-grid electricity, and all the shortfall rules are set to RequirementsRemainUnmet.

When I run the model with optimization enabled for both transformation modules, only one gets optimized. The second shows zero output after the base year, with all the requirements remaining unmet throughout the entire time period (see attached screenshot). After a bit of playing around, I found that the module that gets optimized is the one higher up in the transformation tree; the issue always occurs with the second one.

Do you know what may cause this issue, and how to address it?

Thank you in advance for your support!