As of 12-23-15 call recording is no longer working on Samsung Note 4 N910A running android 5.1.1.
Was working prior to latest ACR update 16.2
ACR works perfectly on your phone. Please remove any other call
recording apps, re install ACR and reboot your phone.
Do not change any settings of ACR what so ever ant test to see if the
issue gone away
Also see this
Figured it out, looks like the audiko ringtones app was somehow interfering
Aha! Everyone is Android developer.!!!