I just upgraded to 4.12.0 and went to look at the Storage Summary screen (Admin -> Storage). I noticed an extra character after the 'Artifacts Size' header. I am not sure if this is new to 4.12.0 or if it's been there for a few versions.
The character is a '썘' and looks like it's in the sort direction field/position of the artifact size column. I'll attach an image.
We're fronting Artifactory with Apache using mod_proxy_http. We use 'AllowEncodedSlashes on' and 'ProxyPass /artifactory <url> nocanon' if that matters.