Well I have a 10month worker and have been having the same problems. He's always been 100% in the past but has recently "gone Deaf", not only to recall but the stop whistle as well. Around the home/garden he will walk to heel off lead brilliantly, recall, and stop on a dime. I can also recall him stop him mid way and recall him in.
I've kind of gone back to basics and doing more training in the garden and put a line on him if I do take him out. He's even started to bolt when his lead comes off and he's usually very steady. I'm hoping it's just a phase as all his training has been going so well.
we go to a group training day once a week and this week I put him in a sit and as he's been so steady in the past took his lead off DOH he bolted and picked up a pheasants head
from the pervious days shooting and would he come back