My wife was straightening her hair today when she noticed that whenever the straightener element turns on, the LED lights in the bathroom flicker. The lights are on the same circuit as the outlet (which is GFCI), there are no dimmer switches installed anywhere in the house, the house was just built, and every single light in the house is LED. On this circuit, there are only the 4 LED bulbs, a recessed led light, the bathroom outlets, and the smoke detectors.
I've noticed flickering before, but have been unable to isolate the cause. I tried putting the straightener on a UPS with filtering, to see if it was some kind of noise being generated, and it did not help.
The flickering is visible on the 4 Feit Electric "Edison style" dimmable LEDs, as well as the (unknown branded) recessed light.