Yep avoid only catching to ride/work, often go up to them in the field, scratch and walk away, maybe give the occasional treat, you need them to associate your presence with nice things more often than work ?
If they do walk away, avoid chasing them but don’t let them stop to eat grass either, keep up a steady gentle pressure (uncomfortable) and give regular chances for them to stop and let themselves be caught (comfortable) and then give lots of fusses and reward and regularly let them go immediately so head collar on doesn’t always = work.