Roof delamination

Thanks all again. I ended up cutting 3 sides of an 8" square piece and then peeling it up to see what was going on. About 1/8" of plywood had separated from the plywood below and the EDPM roofing was still stuck tight to the 1/8" piece. All the plywood looked strong and intact except for the 8" delaminated part. There was no dry rot at all and I could not see where any water had come from any direction to cause this. There are no seams within a couple of feet of the area. I ended up filling the area with epoxy, put wax paper on it and weighed it down overnight with about 50 lbs. of weight. I then covered the whole area with Eternabond tape and the used Dicor lap sealant on all the seems. If this doesn't work I'll always thought it should've.