Please give a link next time as well.
I looks like something specific to your wiki and not like a UCP bug (South Park Archives Wiki is a UCP wiki), since I've looked at other UCP wikis on mobile and they don't have this problem.
However, it could be a UCP bug that only happens with certain types of older wikis that have been converted to UCP.
This problem sounds familiar, so FANDOM staff might be aware of it, but you should still report the bug via "Contact us".