so uh energy is so weird on these puzzles
is it supposed to be like this?
No, it’s not on purpose. You don’t mention the folding engine (which is important), but I’m going to guess this is NUPACK, which has long-known issues such as this.
As Omei mentioned, this is a characteristic of NuPACK - it has insanely large penalties for large loops. It’s not a “bug” per se, just unusual from what you might expect!
yep it is nupack so its not a bug