So why didn't the temperature rise by 1.6269 C deg when CO2 rose from 280 ppm to 420 ppm?
Because you don't understand the difference between TCS and ECS. You took the ECS formula and tried to compare it to TCS results.
This is basic stuff, and you completely faceplant at it. You faceplant at all of the basics. Given how bad you are at this, you shouldn't be bothering the grownups. As it is, you're just a fine example of Dunning-Kruger Syndrome, a person who is too clueless to understand how clueless they are.
Proceed to rage now. After all, it's not like any denier has ever said "Thank you for pointing out my fundamental error. I apologize for insulting people because I was so stupid."