I discovered an issue when I use the YOURLS browser bookmarklet tool to quickly create a shortlink to the page I'm viewing.

I have the bookmarklet "installed" to my browser toolbar with this code as expected (directly from the YOURLS tools page).

When I create a link with it, any + marks that existed in the original URL are removed.
So https://www.bing.com/images/search?q=list+all+modes+screenshot&form=HDRSC4&first=1
becomes https://www.bing.com/images/search?q=listallmodesscreenshot&form=HDRSC4&first=1
which is of course broken.

If I copy the original URL and create it in YOURLS myself by pasting in the admin page, the created link does not lose the spaces.

This makes me believe there is a flaw somewhere hidden in the bookmarklet code, but I'm not skilled enough to know how to debug that.