Galaxy Note Phones lock when call ends

Galaxy Note3, and Galaxy Note4 Edge: When call ends by : 1. Caller hanging up first, or 2. Ending call using BT earpieces (a number of different brands and models) Device LOCKS Note, it does not do that if you end the call first using the buttons on the device screen. Also this problem is with: - Phones that are encrypted and phones that are not. - Phones that have s view covers, or have no cover at all. - Phones that use PIN lock, and phones that use fingerprint lock. Note also that this problem does not occur on S3 or S4 to my knowledge, but that is simply a friend claming that he does not have this problem with his phones