Export to YouTube: Don't want 60fps
I created 3 different movies in iMovie using the same imported clips (mp4). One of the movies I exported to YouTube shows up on YouTube as 720p. The other two show up as 720p60. The 720p60 movies lag severely, while the 720p movie plays seamlessly as all my other movies have. I used the same settings to export to YouTube for all 3 movies. Why would one be different than the other two?? I don't want 60fps videos on YouTube. How can I prevent this?
iMovie 10, OS X Yosemite (10.10.5)