For some reason, after a while, my headset earpiece was not working, but everybody else in a party could hear me.
So I decided to reset the controller (NOT THE CONSOLE) first, but my controller kept making the four flashing lights, but was working fine(?) (The battery was charged by the way)
Here is the funny part of the story though, it can't JUST be my headset, because my chat pad wasn't working either! For now, I am going to assume that it is the controller's fault.
When I shut down my Xbox and unplug it for a few minutes, then plug it back in, the headset and controller (player 1 light by the way) worked fine after(?)
I am guessing you don't have another controller to try? but from what your describing it does sound to me like the controller is the issue here.
try pressing the battery pack firmly to the controller next time the lights blink it could be that the battery pack is not sitting right.
I actually had to take another person's controller to test out my wired headset, so apparently, it IS my controller! Thank you!