I think what might be happening, if that is the case with the bubbler, is that a small amount of water is making its way over the top of the glass, between the glass and the plastic trim. Manufacturers do not completely seal the black trim to the glass, and that looks like what has happened in that corner. The outside seam looks good in the pic, I don’t see any signs of seam separation. Try moving the bubbler and filling back up, realistically your high water mark should only be about a 1/4”, 6mm, above the bottom of the black plastic trim. See if it leaks any more after moving the bubbler.