I noticed a strange problem recently. Whenever I am using the phone (i.e. the screen is on), and I receive a call, the phone rings/vibrates as usual but the incoming call dialog does not pop up on top of whatever I am doing. The phone icon appears in the status bar as well, but all the on-screen navigation buttons disappear and the status bar becomes disabled. This means I can't answer the call, therefore I miss any call that comes in when the screen is already on. This also means that the phone is basically unusable while it rings. Incoming calls work normally when the screen is off or on the lockscreen.
I do run with Xposed and GravityBox, but I entirely disabled Xposed and the problem persisted, so I am wondering if this is an issue that came along with the 4.4.3 update. I can't remember being able to answer a call with the screen already being on on 4.4.2, but I also don't remember NOT being able to.
Does anyone else have this issue or know how to solve it?