It may not be the final solution, but I do think spreading out those edge loops will help alleviate that area for sure. Sometimes the curvature of the model really accentuates those edges pinching together, it can be a pain.
Interesting, it looks like dilation should be fine. Is there any overlap in the high poly mesh at that area? It does look like it could be the area where the array modifier connects back onto itself? I’m sure you’ve already done that cleanup process, I’m just throwing it out there in case it is worth a second look. Truth be told I’m not too sure what it could be, you are only seeing that appear in the AO bake?
