[JoeyP]

"Come" is a foreign language to Yorkies I have found
it doesn't compute
esp when they are outside or doing something they like doing

But you need to make it clear that coming to you is always going to better or in their interest

You also need to do this early and NOT get into the rut of calling their names over and over again without them coming because Then their name becomes only background noise and never means anything to them

You can't train them inn the house to come to you and then expect them to come when they are outside
You need to train them with all the distractions present from the start
Take them outside. have someone take them away from you on a lead
In increasing distances
Call them with a treat in your hand
and have the other person let them go

see if they come to you