Smart Fob Partially Paired

I lost one of my smart fobs to my 2014 Prius a few weeks ago. I acquired a copy of techstream and a cable to connect with the software.

I erased previous key leaving 1 smart key paired (current one).

when I try to pair a new smart key I got off the internet and I follow the instructions (power on, engine off), no keys in vehicle etc, old key on button, new key on button, new key on seat I get a beep and it says the key is paired.

when I actually try to use the key, the buttons work for unlock and lock but the smart handle refuses to recognize the key and the car doesn’t start without putting the new key against the button.

the battery measures 3V and swapping it with my old key has the same behaviors.

does anyone have any insight? As far as I can tell, if my key was “used” it would just fail to program right? Seller listed the FCC ID and board number which matches my oem key.