Already reported. Couldn't find when I searched %, that's why. Please close this issue as duplicated.
This bug has existed since 0.14.0 (Maybe before?) but I thought It would get fixed, but it's still not fixed so I'm reporting it.
% character isn't shown in world chat , but shown on chat list. If you can't understand this, see photos below and test %Test%, %, %%, %%%, %%%%, %%%%% by sending message. And on some % not all % gets hidden; that's why I said to test these 6 examples.