AT light turn on and then off

What is your question?

So it's been 1 year and 8 month from when i changed my transmission computer it cost me 900$ to change it now I have this problem the AT light turns on and off alongside with the parking light when the the car is on park, I recently changed the sparkplugs of my car so i don't know, the AT light indicates that it's a transmission problem but the car is stopped i don't see the logic there and the check engine light is always on I made a video so you can see after a while it stopes then turns on again here's a link to see the video (drive.google.com/file/d/1vTVU9F7RSTGaPfsNFkpOFIxmwarYuAkC/view?usp=drivesdk)

What makes this problem better or worse?

Nothing it comes up randomly and goes off randomly