I've had the same problem with mine from time to time and after a lot of pondering I've simply concluded there is a "sweet spot" for them to operate within and if outside that for bowl dia or depth it can happen. I looked at the Glen Lucas video for some mods to try. Worst encounter for me was on a couple of natural edge bowls where the cutter was out of the sweet spot curve enough for the support finger to catch on a bowl wing as it came around. Nasty instant and destructive stop. In the open air between tall wings on the bowl I think the support finger can swing or move in or out, depending on the bind being on the outside edge or inside edge, and catch. Sounds like you've used yours more than I have but, It's hard for me to believe the steel on the arm and finger can bend or change shape. They're very thick and sturdy but, it does take a beating on some cores.
Bill, have you checked and confirmed they can/do bend? I'll try to find the Chris R video. I've never seen anyone do a video on using the coring system on natural edge bowls. Maybe it's not intended for that.