Is this bad??!! Very light cold sensitivity

[Mayo]

Hi, I have a front tooth crown. This tooth has had a root canal. I've noticed for a while now that there is some VERY light cold sensitivity coming from it when it experiences a cold beverage or food. Nothing major whatsoever, but I have a heightened awareness of my teeth right now so I started taking note of it. I'm scared it means the root canal failed again. Its already had 2 root canal, last one was over a year ago. Is it possible some teeth just have slight cold sensitivity and there's nothing necessarily wrong or is it a high likelihood the root canal failed?

 

[Dr. Daniel]

after a root canal treatment a tooth cannot feel cold. this sensitivity must be coming from a different tooth.