DTI calculation for a vacation home mortgage- conventional mortg

Hello, 

We use our Airbnb in MN as a secondary/ vacation home when we are in town and usually are, about 3 months out of the year+ every now and then for a few weeks each time. 

The Gross revenue was about 31k while the mortgage was around 1500 a month and with other expenses adding up to us not really getting any Net Income. 

We are planning to buy a vacation home in Florida now so the house in MN can be used full time as an Airbnb. The big question is, if The DTI to get eligible for a vacation home(10% down) depends on the net income or the gross income? I found out that it is calculated as per the taxes we filed, and in taxes, there is not much of a Net Profit from the Airbnb. Ofcourse it pays for mortgage and all other costs like Maintenance and Utilies etc, but in terms of getting a new mortgage, will our situation be seen as a positive or negative DTI? We are new to this so a calculated number response will be extremely helpful to wrap our heads around what to expect. Thank you so much in advance