Yeah, a warranty claim might be your best bet. Personally, I've never been able to repair that type of damage in a way that holds permanently. I've only tried on a couple of boards, but it always opens back up sooner or later.
Here's what I've done to try to fix that: Really clean out the area and score both surfaces. Tape up the top sheet and base to protect it from epoxy. Warm up some G-flex epoxy a bit so it's runnier, and get it down in the separation. Clamp it well and hope for the best.