Have you tried to update the software in the head unit. Go to the Kenwood website, plug in the model number and download the latest firmware. Put that on a USB drive and follow the instructions.
Depending on how old your phone is, Samsung doesn't have the best rep when it comes to keeping the phones updated. More recent ones are and android auto has received a number of updates in the last year or so. Firmware update to the head unit can't hurt.