I have a Sprint SPH-L720, unlocked and rooted (versions below) and, when using the phone and I want to end a call, nothing happens - if the other person hangs up, I'm fine, but if I make a call and get a voicemail, I have to quickly reboot my phone since my red "End Call" button does nothing... tapping it like a madman has no effect - the screen shows the button being pressed visually, so it doesn't seem to be a phantom screen lock issue.
I did fiddle with the modem/radio updates, since I am overseas with the phone to get it to work with an unlocked SIM - everything on the phone works fantastic - just the damn "End Call" button which is kind of important...
Using a different ROM and going back to a Stock restore has no effect, so it leads me to believe it's a modem/radio/baseband issue or something.
Let me know what you think!
Android Version: 4.4.2
Baseband Version: L720VPUAMDC
Kernel Version: 3.4.0-cyanogenmod (Sun Apr 20 2014)
Cyanogenmod version: 11-20140420-NIGHTLY-jflte