There are 3 things you need to have when potty training a yorkie, patience, patience and more patience.
10 months is not very long in the potty training department for these little ones. Maggie did the same thing. We would go for a long walk and Hot Rod would do his business and Maggie would pee outside and as soon as we got back inside, she would run over to pad and poo. She turned 2 in May and will still do this from time to time and she did it often up to probably 1 1/2 years old.
One day it will click.

Lately, for the about the past month, Maggie has been letting me know that she has to go outside to potty. Yeah! She seems to be preferring to potty outside now instead of on the pad in their pen. We have a pad in the garage as well and she will use that but not in the house so much anymore. Unfortunately, she woke me up at 5:30 am one more because she wanted out in the garage to poo.