I did not expect all the ants to follow the same path, but I thought maybe they'll come close since only the best generations are supposed to get passed on with mutations. I'm at generation 810 and the model hasn't improved much. Most ants (except for ~6) first go to the right to avoid the obstacle, and then they travel to the upper-left corner while about 6-8 reach the food.

I hope it would work better with minor tweaks to calculating the loss and selecting new generations :) Good Luck