We've replaced just about every bulb in the house with LEDs now, and most of them have had zero issues so far. In the kitchen, we have five can lights that have been in there for a few months, and just recently a few of them have started flickering intermittently. They'll be fine about 80% of the time, but then they flicker the other 20% of the time. One of them has quit working altogether. Did I just get a bad batch? Is this a common issue for LEDs?