Since then they have been terrible communicating with me.

You are blending 2 income methods.

Another method I gain unlisted leads is by talking to the neighbors of every house I rehab.

It seems strange that after 5 years they went dark without any notice or communication.

Since my tenants are usually homeowners it doesn't make sense for me, but even for the couple travel nurses I've had, the background/credit check was sufficient and seeing how they communicate with me prior to booking.

It's how you are approaching the communication.

I have had more success in finding off market properties from people who know me than any other method.

Ultimately, it depends what your goals are on which method will fit best for your situation.  

What specific steps do they take and what do they communicate to the owner?

I’m interested in using private money to get started and continue using the BRRRR method as I love value add and I’m able to do a lot of the work myself.