Has anyone ever had font trouble where, in a browser, an entire section of text is found in the medieval alphabet instead of a readable font? ðððððð Apologies to anyone who regularly reads medieval script.
That’s an issue with the website, or your browser missing the font the website is trying to use.
Very very unlikely to have anything to do with Plasma or any other KDE software.
You may have to install a font set suited for medievalists – such as Junicode. <https://github.com/psb1558/Junicode-font>
Your distribution may have a package named something like – “ctan-junicode-fonts” …