I do have additional coverage for the sewer since I knew it may have issues before I bought the property. 

Since they needed renovations, he invested roughly $30,000 per property to make them rent-ready—bringing his total investment to $110,000 per unit.Once rented, he quickly encountered issues: non-payment, eviction filings, constant repairs, and tenant-related damages.

Hello,I've had some issues with excessive costs through my property management company over the years. 

Give fair housing testers the right to secretly record your call, trying to trap in a fair housing issue.

Can anyone recommend good companies to root cause  and implement solution to fix this issue?

I say to look at these hard because these items can occur for a period of 12 months possibly without major issues of seeing large cracks or settling if a lot of water hasn't been present in large volumes.

With 40% of homes still selling above asking price, waiting for a “better deal” often means missing out entirely.Financing is also a common issue.

The issue is that you cant cold call people in New York 

Of course another possibility that the work done was subpar and the seller has a legit issue with the billing amount.  

- The current low rent is probably to offset maintenance issues at the property.- Try to raise the rent and the tenant will give you a list of all the maintenance issues they want you to fix. --- They will offer to fix them in exchange for lower rent, but ask yourself, if the tenant has been living there for 25 years, why isn't everything fixed already?