I have had a drywall crack repaired several times where the wall meets the ceiling. I finally found out that when the house was built, the drywallers did not butt the wall and ceiling drywall. I've thought about covering up the mess with crown molding but it's a cathedral ceiling.
Crown (or a flat crown) will be the easiest solution. Otherwise fill the gap with strips of drywall, tape, mud and repaint. If the gap is small enough, you may be able to just tape and mud over it.
Note that if there is any movement in your framing that you may see seasonal cracks at this joint. Any movement now would not be detected as the wall and ceiling surfaces are not in contact with each other. So you may solve one problem only to create another.
Thanks, I guess crown is going to be our only solution.
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