Nice guitars. Bought the wife one for Christmas 6+ years ago that was in fair condition. I think I paid $350 and put another $125 in it for a new saddle, nut, and setup.
There's one on the Pittsburgh Craigslist for $399 asked and another on the Boston Craigs for $650 asked. Those are probably...
Some highly speculative answers:
1). Failure to remove glue squeeze-out at that glue joint, causing the finish adhesion to fail.
2). Differential thermal and/or humidity expansion/contraction rates between the two wood species.
3). Because cosmic rays.
Welcome. Stick around - nice bunch of folks around here. I've never seen that in any my Guilds. Have you checked the truss rod? I can imagine a scenario where an over-tightened truss rod might do that. The guitar is adequately humdified?