I believe truly that beaver can get square shy .. Ive seen too much trail cam footage of them avoiding body grips.. Then I also think when you have snapped bodygrips or foot and tail catches its from beaver turning at the last minute, getting close to the trap but not going through..Or trying to pull themselves over it..
Now if your just gang setting for fur it does not matter so much but if your trying to remove them all its a pain.. Thats when I go too all footholds, blind sets, sac oil or food lures..etc

Have had the same problem trying to get a couple adults out of a nuisance job creek. Ended up using my duke number 4s on drowner cables with a castor mound set. I set half way between a front foot target and a back foot target hoping for a back foot after it had committed. Had an adult 2 days in a row and that's a wrap there. Switch it up. If they don't like the 330 give them something else. The most important thing that taught me is to hit them as hard as you can with as many good sets as you can right off the bat. It is much easier to catch the kits after catching the adults and 2 year Olds then it is to catch the youngins and then try to catch the adults. Goodluck and tight chains!