Trying to figure out why mini split air conditioner gives us sore/dry throat every day (it's not mold)

So my wife and I are staying at an airbnb in a condo in Thailand that is brand new (finished less than a year ago).

The place is extremely clean but for some reason we are waking up with sore throats every morning.

I have a mini split air conditioner at home and also have stayed in a few dozen places in Thailand and never have had this issue.

I know it's not mold because there is no smell, and I am very allergic to mold (get different symptoms). Also I cleaned the pre filter of any dust so I don't believe it's dust either.

For what it's worth, I am down in Phuket.

Does any one have any theory to what's going on?