Hi
I suspect that tortoise might not do the URL escaping when the URL is displayed in the title bar as that generally makes it less readable. The zero width space would of course be invisible when not URL encoded. When actually calling it, it must be encoded in accordance with standards.
The title of the first window also states https but the commit window then calls http. Did you really open that repository browser from the context menu for the same working directory that you are then trying to commit? Perhaps you opened the repo browser and pasted the URL separately there?
As Stefan said, you can try checking out to a fresh working directory. You can also use Relocate from the menu to check and edit the working copy URL. To remove the invisible space, put the text marker after the s in search, and hit backspace twice. If the slash is now still there, it means there was an invisible character. Retype the s and proceed.
I guess it's also possible that the zero width space is an actual part of the repo name in which case the encoding is correct and the problem is something else.
/Oskar