It's somewhere between difficult and impossible to diagnose a vibration over the internet. It's hard to describe and impossible to feel.

That said, assuming it is indeed a driveshaft vibration, it is common for the single u-joint to wear in a very specific spot. To move the rotational location of the pins in the u-joint. Loosen the carrier bearing mount bolt on the drivers side and remove the bolt on the passenger side. Place two washers between the mount and the body and put the bolt back through and tighten both.

This will sometimes erase such a vibration. It costs nothing to try.

If it is NOT at driveshaft speed, then rotate tires front to rear and see if it changes.

Good luck,