When you add a space in the name of the Page the logo doesn’t display in the top left-hand corner.
For example, i just did test test and I see the word ‘Universal’ not the image.
Click on the image to open in another tab and the page url is /test%20test/logo.png
The HTML simply has img src="logo.png" but yeah, it’s trying to fetch the image from /On%20Leave%20Today/logo.png. Not sure that the spaces in the page name are really the problem here! More a relative-path thing. I guess it’s really trying to grab /admin/logo.png.
EDIT: Renamed my page to just “Leave” (even though the path was always just “/leave” with no spaces) and now the logo renders. So yeah, surprisingly the spaces do have an effect!