Replaced battery in remote, not working with the car

[jrfk2]

I have a 2017 Impreza and one remote started not to not work with the car, but the emergency button would still work. Took out the battery and didn't have the right size to replace it with. left the battery out and got a new battery and when I put the new battery in, the remote is not working at all with the car, not even the emergency button. Did the remote forget the settings for my car since I left the battery out? Tested the old battery and it still had a decent amount of charge so maybe the remote itself was going bad? Any suggestions / advice? thanks ..