Issues with a Key fob that was working

Hello, I have been on multiple sites trying to troubleshoot my issue, but I have had no luck and hoping for some guidance. We had just purchased a 2009 Prius from an original owner. He had both key fobs, one worked but the rubber clicky part was all worn thru (I'll call that key A), the second key looked fine but only started the car, would not do the smart lock feature, said he dropped it and it stopped working, (Key B). So I went online and bought a new housing from Amazon, thinking I could get Key A looking new again. It already fully worked so thought it was a simple fix. I cracked open the old case, slid out the motherboard looking thing and put it in the brand new housing. Yes, it was the same silver logo housing as the old keys. So thinking at least one key worked and looked nice was a mistake. It would unlock/lock the doors but suddenly would not start the freaking car anymore!! The other key luckily still started the car. But now we had to carry 2 fobs, one to unlock and one to start!! So, I found the chicken dance, tried that but no luck after multiple attempts. The anti-theft light does not stop blinking after the last step for procedure A, like 10 mins I sat in the car with it still blinking. Saw a post saying the chicken dance may not work if the batteries were any bit old. So I replaced the batteries and somehow that got Key B to work, but it was in an old housing which also slips apart if you look at it sideways! What I am trying to find out is...Can the Key A, which only unlocks the car, somehow be fixed to start the car without the chicken dance? I don't want to try and replace the housing for Key B because that is how I lost the start function for Key A. I am obsessed with trying to fix this myself but running out of options! and I am sure the button is not disabled under the dash or Key B would not work. H E L P!!!

 

THANK YOU!!!! That was it and it works now!!! Thankfully I still had the old piece!