Can you help me figure out why a post image adjustment is not taking?

Hi,

I was trying to swap out an image in a post today. The image needed to be adjusted in order for it to appear in full so I selected "Fit" and "Center" and then clicked "OK". The image continuously returned to its former state. I was so unsuccessful in getting it to fit that I had to find another image and work with it.

I'm hoping you can help me so I don't go through this again. I've attached screen captures to confirm what I've shared above.

I look forward to your response.

Sincerely,

Kimberly