I have made a few videos, uploaded them into my account, but when played in one of the players (yes, correct player), they end up playeing with a black bar on top and bottom and the video is streatched out to fit the width. Why does this happen and why aren't they saving as full 16:9 videos?

I have the 16:9 option selected and the videos are being saved as H264 videos. Here is what I was told:

I see that all the renditions are squished top to bottom. But the source file, when played in VLC appears very slightly squished from side to side.

What can I do in the program to set it to save all videos 16:9 and "solid" or "flattened"?

I attached an image of the size settings and how they're saved. -