Problems with heat recovery system (of the ventilation system) after adding add zone mixing object

Together with a fellow student, I have to model a residential building in OpenStudio. We have made a lot of progress, but we still have the following problem:

We think that the airflow between different zones is very important, especially in residential buildings where you have an outside air supply (coupled with the heat recovery to ensure the correct supply temperature) to various zones. Which then flows through a zone (like a hall) with no supply air or no extraction air. Thereafter, an airflow has to be possible from that zone to another zone (for example a bathroom) provided with an exhaust fan to extract the air. ( just for your information, we didn't draw any interior doors)

To implement those airflow's we used the add zone mixing object and manually balanced all the zones. We didn't get any extra errors or revere warnings after simulating, so we thought everything worked well. However, when we zoomed in on the heat recovery, we saw that it no longer works. We conclude that adding the Fan Zone Exhaust occurs problems with the heat recovery system, which makes sense because those exhaust fans aren't coupled with the main ventilation system.

We are looking for a correct method to couple our exhaust fans with the mains system (with heat recovery). I don't know if this is possible? Or, are there other ways to model a good airflow?

Before using exhaust fans:

After using exhaust fans:

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Are you using this Add Zone Mixing measure from the BCL? This will incorporate one-way mixing, but not related to the pressure-driven airflow network. I ask because you included the airflow-network tag in your post.