Optical Flow Flash/Glitch in Edit

Hi, 

So I've noticed this glitch for a long time and I have been searching around the internet without much success for a fix. 

I've noticed that when I slow down footage and there is a camera flash or the sun in bright something like that. (Which happens a lot as I am a wedding videographer)  Then once rendered there is a big distortion or glitch that happens where the light is. 

Does anyone have a work around for this or any suggestions on how to fix. On some shots using optical flow is just needed so I'd rather figure out a way to make it work rather then avoid using OF altogether.

Thanks in advance for the help