Why don't some LED lights work in my ceiling fan?
Because of the way LED lamps function they are often incompatible with incandescent lamps in the same fixture.  LEDs are small electronic components that work off of 3-5VDC, but are usually in series strings that take 12-24VDC. So in the base of each LED lamp, you have a printed circuit board called a &quot;driver&quot; that is basically an AC to DC power supply for the LEDs. Depending on the design of the LED string inside of the bulb, some types of drivers can be affected by being on the same circuit as incandescent lamps because the LED driver has a higher impedance than the incandescent filament.
So although I have seen several websites saying it's fine to mix them, that is incorrect, you should go all one way or all the other. In fact even if you have all LEDs, the drivers in each different brand are different and can be affected by each other, so it's best to use all of the same brand on a fixture.