Do you yell/bark at them to try and get them to stop ?
I've seen very few that wouldn't stop for a good look back once they feel safe out there.
If i have a coyote come in from behind or just milling around way out but won't commit -i spin around into a prone position -put the handcall in my mouth -get lined up on the coyote and blow the call as loud as i can -be ready to shoot when it stops for a look.
I've had them hide behind sagebrush and peek out never offering a shot ,once while laying prone i had one staring from 300-350yds -i curled my leg up and twitched my boot back and forth until it offered a shot -hit a sagebrush limb about 25yds in front of me -oh well.
Over calling is one of the biggest mistakes made -imo-.
If you get one leaving out try the call and be ready to shoot when it stops.