Nasal Pillows and Post Nasal Drip

I've been using the Swift FX for her nasal pillow mask for the last 8 nights. I prob sleep 4-6 hours a night. Today I had post nasal drip all day. I'm not sick. Is this from the pillows or cpap in general? I'm new so I don't have mask choices yet. Waiting for my doctor to send me the prescription so I can purchase one on my own.

It may be from the humidifier setting. Some people need more added moisture and some people need less.
Too much or too little moisture can actually produce allergy like symptoms...congestion...runny nose, etc.
People have different needs so you may have to experiment with more or less humidity to see if you are one of those people.
Of course it might also be simple allergies too an unrelated to cpap but you can play with the humidifier settings to see if it helps or makes it worse.