Temperature of Nodes around heat exchanger is not reasonable

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I used OpenStudio to model a high school buildings in the cold area. There are heat exchangers in its AHUs for energy recovery between outside air and exhaust air. After checking the modeling output in ResultsViewer, the temperature of two nodes around heat exchanger is not reasonable for me. When the OA Temperature (Node 237) is low and exhaust air temperature (Node 213) is high, the OA temperature after heat exchanger (Node 212) is higher than exhaust air temperature after heat exchanger (Node 209), which is not reasonable for me. The detailed air loop and temperature variation are showed as followings. Does anyone know why it would happen? Thanks!