I am new to my 6D, but not DSLR photography or strobist style flash photography. I was taking some pictures today for my side business and when editing noticed that in one of my pictures there is a streak on the right that is washed out. I am not sure if that is due to one of my flashes being very close camera right, w/ shoot thru umbrella and at 1/4 power. On some shots I had to crop out the umbrella since it came out in a few pics. The other pictures look fine to my eyes. Any help would be appreciated.
EDIT: I tried to recreate the picture, but didn't get the same result and I don't remember how I was positioned.
Not sure where I should put this, so if it's in the wrong section I apologize.