Gen Suggestion Discrepency

When I use the Gear Explorer and click on Auto Gem/Enchant it does not recommend any changes. However, when I then do BiB, even though no gear changes are recommended, it suggests changing the gem on head piece to Crit. Why is this? Which one should I believe? I can only put one attachment so only screen shot of Auto Gem/Enchant.

If you post your export string from the addon I can look at your Best in Bag and check it out.