I got a very lucrative multi-day booking this fall, and then tried to cancel just a couple of weeks later claiming I want except her service dog which wasn't true.

The tenant will claim your service sucked and only tip you $200. 

They still do not have an app, although they claim to be developing an app.

@Mohammed Islam, The claim of loss due to the tenant moving out for the sale COULD absolutely apply to the situation.

When they pay out a claim, the money comes out of their pocket.

No reason they could claim discrimination for a rent increase.

Accurate records of all expenditures are essential to claim deductions and calculate the cost basis for future capital gains taxes, including depreciation recapture.This post does not create a CPA-Client relationship.

A quick internet search led to quite a few complaints by people claiming to be ripped off, had deals fall through, or simply getting the run around each time. 

(in which they did)  then pay the price, or another tennant will🤷 You made the claim that your tenants were now "happy" to pay a $400 rent increase.

Best thing to do is avoid the higher DTI debt to income, claim one as investment and use the rents to offset the new purchase.