While I don’t have the expertise to advise exactly what’s wrong here, I will say that if you’re worried about anything getting in/out from ventilation holes, just grab yourself some of this and hot glue it over the openings that you create. Works well! https://www.amazon.com/dp/B09C8FD8N9 Though you need something like these to cut it: https://www.amazon.com/dp/B000GJBLG2 And of course be careful of the super sharp edges after! I just make sure to coat those with the hot glue as I lay it down.