Yes, often when you seal your house to keep PM2.5 low, your CO2 values go up.

We measures this in classrooms [1] and I also wrote about the benefits of positive pressure systems to have near zero PM2.5 and low CO2 at the same time [2] even on heavily polluted days.

[1] https://www.airgradient.com/resources/we-measured-the-co2-le...

[2] https://www.airgradient.com/resources/positive-pressure-syst...