MSHP capacity suddenly drops by factor of 0.5

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I am using ResStock to simulate heat pump energy use in Maine.

I am simulating for three different communities. For two of the communities, the average heat pump heating capacity is around 40 kbtu/hr. For the other one, the average heat pump heating capacity is around 20 kbtu/hr. I am modelling SEER 15 and SEER 20 heat pumps.

Any idea why this could be happening? The climate is very similar, so I expect the heating load to be similar as well. The average capacity should differ a little bit, but not by such a large magnitude.