2013 toyota corolla ZRE T 82R

Hi, I have a problem with my remote locking keys. They lock and unlock the 2 back doors and trunk only, not the 2 front doors.
I have to lock the car with the key. Batteries are good in both remotes.
The turn indicator lights flash twice when I unlock with the remote, but nothing when I lock.
This started happening with both front doors at the same time.
Hopefully someone knows their Toyotas as I'm stumped.
Thanks in anticipation,