Peel off the tape. You might as well fix it now. First off how long is the
problem area? If it is 4 feet, you probably have a butt seam, and this is
going to be a little tricky. If it is a long seam the taper probably left
too thick a layer of mud under the tape. To fix this you need to get mud
sanded down so you can re-tape the seam and have enough room to set the tape
under the tapered edge of the sheetrock.
If this is a but seam you are going to have to cover over the tape without
the help of the taper. This means you need to make a inconspicuous pile of
mud about 16 inches wide and 1/16 thick in the center.
You also need to be sure the panel is secure to the joists. Push up and see
if the panel is floating. If it is screw it down securely before mudding.
About the time I had mastered getting the toothpaste back in the tube, then
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