2008 Prius - only rear-passenger turn signal / hazard light works

If the hazard lights are turned on, only the rear-passenger light blinks. (nothing blinking in front)
If signalling a right turn, the rear-passenger light only blinks rapidly.
If signalling a left turn, no lights blink.
Signalling either left or right turn, the turn signal indicator on the dash blinks rapidly.
Checked the bulb in the rear-drivers side and it looks okay.

Not sure where to start diagnosing this. Any help appreciated.

The BCM in the vehicle may be failing.

Tester