Almost all Torch Down Flat Roofs have this common problem. A roofer would use a torch to adhere the rubber membrane to the metal drip edge or flashing. The membrane over time will shrink, harden, and pop loose from the metal.
The solution is to pop the membrane loose and use Karnak 66 or Karnak 81 Trowel Grade adhesives to attach the membrane to the metal again
Waterproofing and Leak Specialists