Soap stuck in a plastic mold. Just had this problem, with some new recipes with a lot of softer oils, sweet almond, walnut, apricot kernel. Guess that is too many soft oils in a batch, even at 5% each.
One mold is a Dollar Tree drawer divider, the other was a flat plastic mold from WSP with the 9 little squares. The soap is soft!
I tried freezing. Even for 9 hours while at work. Nothing. Just made it softer really. These soaps have been stuck for a week.
This morning I got up, remembered I have a gas stove. Hmmm, I thought. There is always a tiny bit of heat in there. Put them in there on a cookie sheet, did not turn on the stove. Left for 1 hour. Could have went 30 minutes as the bottom of the loaf one is soft now. Anyhow, they popped right out! Hope that helps someone with the same issue.