Make sure they are loaded, preferably hyper loaded. Beaver don't blunder obliviously through a snare and will back out of it when they feel the pressure.
Natural pinch points with some castor added are my favorite sets.
I have not seen that at all. Now I am not saying you are wrong; however, I ran two trail cams shooting video on beaver snares for a couple years, and I still have a lot of the videos organized into categories that I can review. In all of those, may be 50 good snare catches and a few misses also, not once have I ever seen a beaver back out a snare. In fact I have never seen a beaver take more than one step backward before twirling and going the other way or sideways. I have even wondered if perhaps beaver either can not, or REALLY dont like to go backwards.
Now I have seen them study a snare carefully then turn around, I have seen them bulldoze a new path around the snare, and I have seen them stay 10 feet away and swim back and forth tail slapping, have seen them rear up and come down on top of a snare then walk right over it, I have seen about everything except walk in reverse more than one step.
All of that said, I also load my snares, but not hyper-load because I find that with the right size loop and the correct load at the correct height for the bottom of the loop, I can have raccoons walk right through - the record is something like nine one night before a beaver got there, then along come a beaver bulldozing through and is caught. So I have tweaked my beaver snare setup to where maybe one in 50 raccoons get tangled, but only one in 50 beaver makes it through WITHOUT getting tangled. It does happen both ways though, every few weeks I have to let a coon go, and when I was running video, maybe once every couple months a small beaver would go right through the loop without being caught.
Things can be different in different regions, and I may just have directionally challenged beavers around here, so again not saying you are wrong.
Nowadays I only run video when something is making me scratch my head. Worth noting that I have a camera on one of those right now, and my hair is frizzy from scratching too much…