They aren’t able to get a mortgage themselves so they would provide the money while the mortgage and deed would be in the others name.  

You must provide accurate, current, and complete information during registration and keep your account information up-to-date.

@Caryn FischerI agree with Jaron, you should definitely have a consultation with your tax accountant and/or financial planner before you do anything. 

If it concerns you that much, adjust the purchase price to take into account this added risk. 

So if your interest payment is $1000 then the servicer automatically ACH debits your account that plus the servicing fee (assuming you set up automatic payments as @Christian Ehlers suggests).

After years of self-managing our single-family rentals, we decided to hire a property manager to provide full service management.

Quote from @Danielle Levy: Lesson learned: provide the full story up front and you'll get better advice.If you feel there's a case, put together all the evidence.

They get an ACH from my tenant in their account same day, but won't do the same into my account.

While no property is too big or too small for a cost segregation study, it’s important to speak with your accountant to ensure the benefits outweigh the cost of the study.

Unfortunately, I think you should eat the cost on this.If you have a door that can lock, you should provide the key.