I agree local banks and credit unions will be better if you're planning on growing your portfolio. 

I was working with Kiavi on a DSCR cash out refi 75% LTV on a SF home in NC that is rented to a long-term tenant.We setup the application, credit came through and the appraisal came through for both value of property and the "fair market" rental value.

I'm just buying my time and making some connections while I build my credit history again - worst part about moving country haha!

Walking score of 95.Pre COVID rental numbers:Monthly gross rent $15,250Cap rate 7.1%Future rental numbers:Estimated Monthly gross rent after current tenants move out $13,950Cap rate 6.5%Because monthly rent looks to be about 20-30% more if you rent by the month, I am considering renting out my duplex for monthly rentals on Airbnb/other sites and potentially for travel nurses (ideal because several hospitals are walking distance to my house).

It only happened once, so you have no evidence that this is anything but an honest mistake that's been corrected.The bigger concern is the 583 credit score, because it shows a pattern of financial mismanagement.

Any good recommendations for the collection agency or any way to get the money back from the tenant or any way to report it to the credit bureau?

If I were in your position, I would look for a bank or credit union that will give you a line of credit against the rental property.

I have a lot of bank accounts and credit cards and it seems impossible to keep track of everything.

Read some other comments - I guess it is technically a cash out refi, but you're paying off a line of credit as opposed to putting the cash in your pocket which is what I typically think of when there is a 'cash out refi'.

:Class A Properties:Cashflow vs Appreciation: Typically, 3-5 years for positive cashflow, but you get highest relative rent & value appreciation.Vacancy Est: Historically 10%, 5% the more recent norm.Tenant Pool: Majority will have FICO scores of 680+ (roughly 5% probability of default), zero evictions in last 7 years.Class B Properties:Cashflow vs Appreciation: Typically, decent amount of relative rent & value appreciation.Vacancy Est: Historically 10%, 5% should be applied only if proper research done to support.Tenant Pool: Majority will have FICO scores of 620-680 (around 10% probability of default), some blemishes, but should have no evictions in last 5 yearsClass C Properties:Cashflow vs Appreciation: Typically, high cashflow and at the lower end of relative rent & value appreciation.