MOV video downloads with washed-out colors instead of MP4

Up until a few days ago, any time I downloaded a video from the cloud to my computer, it would show up as an MP4. Now, no matter what I try based on previous threads here (ie using most compatible, etc) the video still downloads as MOV and the colors of the video are severely washed out. So even if I changed it to MP4 once downloaded from the cloud, it would still be a very washed out image. What changed and how can I change it back? This is my livelihood. I am editing videos daily, and need the same quality I had 5 days ago!

[Re-Titled by Moderator]

Original Title: MOV vs MP4