Rubber bands seem weaker when wiggling than they used to be. It takes longer for the protein to start to move, and it doesn't move as much as it used to with bands. This is true in hand folding ("w" key) and scripts (structure.WiggleAll, do_global_wiggle_all).
Many of our "bander" scripts (the ones that place bands and then wiggle, hoping to move the protein) are not working well, and this may be part of the reason. These scripts are a mainstay; I believe most people use one or more of them on every puzzle. It seems like the bands are just not pulling as hard as they used to, so they are not moving the protein much.