I became a landlord by default 10 years ago when I bought a restaurant with attached rental properties ... which I have since sold. 

I think in general what could be happening is that there is some sort of "preferential attachment" where the best deals, the most houses, go to a relatively smaller amount of people a part of the right firms or have spent many years building contacts and expertise. 

The strange thing though, is that the MLS shows the home to be 1,895 sq ft even though the sunroom is heated and cooled, and attached to the house securely, with windows (this sunroom is an amazing add-on and in great alignment with the rest of the home compared to other sunroom mods I’ve seen).

Ask if you can attach a miniscule camera to their house exterior facing your property!

It's a 3bed 3bath floor plan with an attached 1-car garage.  15-20 minute drive to the beach. 

The neighbor who is attached is the one and only eye sore on the block. 

The strange thing though, is that the MLS shows the home to be 1,895 sq ft even though the sunroom is heated and cooled, and attached to the house securely, with windows (this sunroom is an amazing add-on and in great alignment with the rest of the home compared to other sunroom mods I’ve seen).

I have three homes, some of which I've subdivided into individual units, one of which has an attached granny, one a remodeled garage studio, and another in which I just remodeled the master suite add-on into a large studio.

Side question, does square footage calculation on mixed use property for FHA factor in the area of an attached garage?

I send off market deals to my investors with no markup or representation fees attached.