I had the same exact problem! I spent over 3 + hours on the phone with TT and they were unable to resolve the issue. When I opened my 2018 TT backup - all information for both rental properties were there - so it was not a "corrupted file" and it transferred all of one property but none of the 2nd property. I ended up manually recreating (UGH) my depreciation schedule and recreating everything down to initial purchase info for the 2nd rental. I tried every conceivable way to transfer (as I had both a cd rom and usb stick of the data) but to no avail.
To recreate, I just began as if it were a new rental property and then recreated all from the 2018 return. Be extra careful when you are entering your prior years of depreciation and the date you first acquired the property.
Hopefully, TT will conduct further research but after talking with 3 different tech help folks - they seemed to just want to blame my "corrupt" file.
Sorry I couldn't offer anything more helpful than the misery of redoing it all.
