So it appears like two issues here...
1. You damaged the edge. Maybe too shallow of an angle or whatever.
2. You didn't fix the damage when sharpening.
So you need to discover what caused the damage, how to not have it happen again, and how to fix it now that it has happened.
I would be willing to pop some cash into the bin that you sharpened this knife before with some heavy low grit stone like a DMT XXC or something similar. When you apply to much pressure you create micro fissures which dont appear right away but are there, then after a few sharpening touch ups you end up with these cracks. Just re sharpen using lighter pressure on the low grit stone and or rework the edge using something that isn´t to aggressive. Sorry to drop the comment so late in the chat.