Hi,
I dont know if you got your problem fixed.
I have / had the same problem (just began a discussion here, but is not official up to now , see my post xxx Global preferences (language, currency) occasionally change without knowing why! xxx when official)
Same: Support doesnt help.
But meanwhile I think I know what happened.
AirBnB still collects 16% (thats the IVA or VAT) plus 3% occupancy tax from the guests.
But as far as I could figure out, it only works, when your account (global preferences) is set to language = Espaniol (Mexico) and currency = Mexican Peso. And these global preferences change occasionally. Dont know why.
Go into your account info and set global preferences to Mexico (also session preferences ..., everything, i dont know what exactly). Wait for some minutes and make a test inquiry and check if you would have to pay 3% or 16% on xxx Impuestos y tarifas sobre el alojamiento xxx
For me this workaround works, but I have to check every day, at least everytime after log in into AirBnB (like now .. I bet I have to change global preferences again to Mexico because I wanted to tell my experiences ...)