Led fan light flashes when off
The answer likely is get a better bulb.  

I couldn’t follow your installation description exactly, but the “fan control” and the bulb are not compatible with each other.  The control leaks a little bit of current when it’s “off”, that builds up in the bulb and dissipates with a flash.  

Pick a name brand (Phillips, GE, etc) bulb that is labeled as “dimmable” (even if you aren’t dimming).  This caliber of bulb quality should solve the problem.  The electronics or driver that coverts voltage for the LEDs is just too cheaply/poorly made in the bulb that you have, it’s fine for circuits with physical switches, your “fan control” isn’t a physical switch tho, it’s an electronic switch that leaks trace current thru the bulb.