when you entered the type of property for depreciation purposes you probably selected residential rental. you must select commercial and then the 39-year life will be used.
Residential properties depreciate over 27.5 years, while non-residential properties depreciate over 39 years. If the short-term rental only averages 30 days or less as an average rent period, it would classify as transient. It is therefore classified as a commercial property and depreciates over 39 years.
