LED bulbs flickering
Check the voltage at the lamps. If it is nominally 120 VAC, a bad neutral connection could cause variations well over that due to uneven splitting of the line voltage. The power supply in the LED might be overheating due to over-voltage.

Also check if there is heavy fiberglass insulation above the light fixture, preventing convection of heat from the lamps. A larger fixture, with a wider-diameter plate against the ceiling, might serve as a better heat sink.