Logo customizer not working

I am currently working on developing a child theme and have noticed that the logo uploader in the customizer is not working. Has anybody experienced this before or does anyone have any idea how I could fix it?

When I change from displaying dynamic text to displaying an image logo there is just a blank space. I can’t figure out why this is..?

My site is not live so I can’t include a link but any help would be greatly appreciated.