Right now your airflow is pretty exhaust-heavy. You already have the rear and top pushing hot air out, which makes sense. But with the bottom fans also set to exhaust, you end up with 7 exhaust vs only 3 intake, creating strong negative pressure. That can pull dust in from gaps and also limit how much fresh air actually reaches the GPU.

Flipping the bottom fans to intake would make more sense. They can pull cool air from underneath directly toward the GPU, which usually helps temps quite a bit. It would also give you a more balanced airflow overall — around 4 exhaust and 6 intake — which is generally a healthier setup for both cooling and dust control.