I had something similar happen to me on a friends Quickee wing. He brought the airplane over to have it covered. upon initial inspection, I did not like the gaps in the wing sheeting(foam core wing). I sprayed a bit of water on the gap, and filled it with Model Magic. Off to the hobby shop we went to pick out the covering colors. Upon our return, I was shocked to see that the sheeting had lifted. He wanted a light wing, so he went "easy" on the epoxy. I had no choice but to break out the Exacto #11 and go to work. It will be easier to fix than you think. Go ahead and cut it as suggested before. Re-fit it and glue it back down.

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