The key, I think, is to watch it feed several days before leaving. We have to buy a new one every time we take a trip. I have to modify (make smaller) the pickup end of the tube with scotch tape to get it to feed the right amount. Flake has ALWAYS jammed in every kind I have used every single time so I use pellets only in auto feeders. I found that the ones with the orange tube through the canister to work better than any others.
Sorry you lost livestock. Next time set it up early and watch it work on it's own for a few days.