Looks like it's getting too hot. You can insulate less and watch very closely. As soon as gel reaches the edges of your mold, remove the soap to a place with good circulation to cool.
How do you do your cpop? Sometimes pre-warming the over to 170, turning if off and then putting the soap in for an hour or so will get you to gel, sometimes longer. Depends on your recipe, your mixing temps, your FO and if you have other things in that will heat up the soap (sugars, milks etc..)You'd have to experiment with that to know how long to let it sit in that warmer environment.
I've found that I can't have the oven on while my soap is in there, even a 170 degrees. It always gets too hot and I get bubbles on the bottom and/or sides at the very least. Sometimes, I warm the oven and let it sit for a bit after turning it off before I'll put the soap in.