Hi, when you got root canal treatment(RCT) done? X-ray shows no abnormality in the root tip area, actually one of the teeth is underfilled. If you have any pain or discomfort then you have to go for re RCT. Regarding crown fitting it often happens, sometimes Dr will do minor adjustments to the crown and sometimes we will repeat the impression and crown so that it fits better.
Next Steps
So if crown fixation was done recently then you must go to your Dr and tell your problem.
Health Tips
Don't be with an ill-fitting crown as it might lead to other problems not only that tooth, but other teeth also get affected.