I've had a sinus infection since getting a crown, could the crown be the cause?

I got a crown a year & half ago on a upper tooth that had previously had a root canal. Since then I’ve had a persistent sinus infection in maxillary gland & ear infection only on that side of my face. I’ve had several x-rays, seen my Endodonist ,everything looks good. Do you know what could be causing this? Is it the crown?