side by side clips blank gap in between

I am trying to put two video clips side by side, both clips were taken with my iPhone 6s, no change in any settings for the video clips between the two, but when I try to edit them in iMovie, with side by side picture option, there is a big black gap in between, as shown in picture, can anyone help me with removing that gap. Not sure what I am doing wrong , but the gap is soo annoying. I have this clip on youtube, I can post the link if anyone is willing to take a second look there (not trying to get free clicks on youtube).