Three thoughts from me, in addition to the already good suggestions you've received...
First, I'm a fan of measuring, because without that it's mostly guesswork. You could have a company do a point-in-time measurement, or you could get a device like this...
Airthings View Plus | Complete air quality monitor. A device like that monitors numerous aspects of indoor air quality, and they've added particulate matter (PM) to this new unit. Continuous measurements would allow you to determine what fan speed you should run the air filter, whether you have enough filtration, when you cook or vacuum what particulates are raised to, and how long it takes the air filtration and ventilation to return from elevated levels to baseline, etc.
Second, speaking of ventilation, since you're already running an air purifier, the next step if you still suspect poor indoor air quality (or it's revealed through measurement), is adding ventilation. If you don't open your window for fresh air, and or if you often have your door closed, it's possible there isn't much fresh air being introduced into your room. This combination will not only lead to higher particulate levels, but also higher CO2.
Third is to be diligent about the use of the kitchen range hood to ventilate when cooking (which must be vented to the outside in order to be effective). If you don't have a proper make-up air setup (most homes don't), you should crack a window when cooking so the bad air that's expelled by the exhaust fan is replaced and balanced by fresh air. This is especially crucial if your kitchen range is gas, but all cooking releases air contaminants that should be managed.
I suppose lastly, most vacuums will elevate particulate matter levels in the air because they do a bad job filtering what they're aggressively picking up off of surfaces, so vacuuming dried bird poop and dander is almost guaranteed to fill your room with ultra fine nasty things in the air, therefore run your air purifier on high and open a window every time you vacuum, and stay out of the room while the filtration and ventilation have a chance to do their thing.