I installed SuperSU on my dev phone (
ro.debugable=1). I have the proper su binary (PIE OK) installed in BOTH
/system/bin. The SuperSU APK is installed in
/system/priv-app. The APK is the only one on my device (I don't have any other SU apps installed).
When I restart and open SuperSU, it tells me "No SU binary installed, I cant install it etc."
I am running Android 5.1 and using SuperSU 2.27 beta.