I can confirm that there are definitely problems with Android Auto after update to .138
I have lost GPS position twice last week following the upgrade and twice today.
To be sure, I deleted Android Auto cache and data and restarted my phone.
I started the route normally from google maps on the phone, connected the phone via usb cable to the car (Toyota) and started driving. Everything was okay for 5-10 min, but then the position on the Android Auto screen stopped updating. I had to unplug the phone and reconnect it to get the correct position. Again, after some time, the position was off.
This is a serious problem that can seriously affect users, and can lead to life-threatening situations.