Tenant also claimed that because of Covid she will not do a final walk through with me on Sept 30, but would just leave all the keys inside the property.

It's "Notice of lis pendens" and it basically means that there's been a lawsuit filed against the property usually when there's title dispute.As an investor, don't get emotionally attached to properties because it will end up costing you more money when you can't just walk away.

They just want to be able to walk away from it.  

If your company was one that had the foresight to build a tech stack that had dynamic solutions to operate efficiently both on and offline, then 2020 was a walk in the park.

This was probably the 5th or 6th duplex I had gone to look at, I walked in and immediately knew we needed to buy it. 

.- walk the property with a contractor or specialty contractor(s) (electrician, plumber depending on the issues) to get an estimate(s) of the rehab.  

If the homes are very old and in rough shape, walk away.

If you paid full price for your rental and did 80% LTV, even in this bizarre market, I highly doubt you'll walk with much 10 months later. 

I've been more than willing to cooperate and draft the necessary documentation to protect their investment, but they have since changed their position/requests several times and are now demanding that I transfer all assets to them and walk away. 

Make sure you use a realtor that can help you walk through how to cash flow your property and have a good exit plan in case you want to scale.