I suspect that a litter of coyote pups birthed nearby tends to acclimate to your presence and gets more comfortable than the preceding generation. Just a theory.
That’s a great guess. Thanks! When the weather looks like it’s going to get wet enough, we’ll finish fencing and probably get some yaks (too cold and too much ice for cattle). That would solve the problem. Yaks require slightly better fencing and will chase predators away.