I have tooth sensitivity on tooth 14, upper left side. I had a root canal done and a crown. What’s wrong with the tooth?

I have a crown that is almost 2 years old (Tooth 14 Upper left side), recently I feel sensitivity to that tooth and I had a root canal done around 4 years ago. I do not feel sensitivity to hot or cold or even when I tap or put a lot of pressure on the tooth. However, I feel sensitivity sometimes when I glide or bite down certain ways, did my tooth get a cavity under a crown? I have seen few dentists and they could not give me an explanation any ideas what’s wrong with me?