Are they professional in their interactions?

Readers should seek professional advice.

In addition to that, platforms like HomeAdvisor or Angi are great for finding vetted professionals, and local builders associations or the Greater Beaumont Chamber of Commerce may have directories or recommendations. 

I am experiencing similar issues with time of year being the main culprit.

These successful managers are highly experienced and manage a large number of properties.ConsiderationsLocation is the most important investment decision you will make.

My advice on sub to is as follows1- COMPLETELY understand the process, implications, liabilities, and possible outcomes before engaging or attempting to engage in a sub to transaction2- Complete disclosure going so far as making sure the other part understands the transaction and possible consequences3- Utilization of an attorney experienced in subject to transactions for setup in such a way that provides some protections in case of default or in case the note is called4- Have a backup plan in case the note is called5 - only use for property that has a TRUE positive cash flow unless the buyer has substantial reserves I myself have purchased 8 properties subject to, but 5 of those were commercial properties which often have notes where a subject to is allowable.  

Did you work with any real estate professionals (agents, lenders, etc.) that you'd recommend to others?

Would love feedback and learn from the seasoned professionals. 

Readers should seek professional advice.

A PM is a professional in managing property, not plumbing.