Hello @jessicah 

1.  You could try to get the upstairs powerline units  downstairs, and pair them one by one with the one of the working powerline extenders (in case mess up  the main powerline unit connected to router)

Later plug them back to upstairs wall sockets 

Here are some tips to manually pair the powerline units

• Put 2 powerline unit in the wall sockets, in the same room, and pair them again :

Paring Note:  press Pair button only for 1 sec, Power Leds should be flashing on both powerline units in pairing process. ( if the Power Led does not blink, press it for 1 sec again)
FAQ258: How to secure (pair) the Powerline Network?

2. Please download tpPLC Utility and connect computer to the working powerline unit see how many powerline units are paried in the powerline network:

https://www.tp-link.com/support/download/tl-pa7010-kit/

You could also use tpPLC utlity to add more powerline extenders:How to add a device to the network using tpPLC Utility (new logo)?