In Azerbaijani (az) and Turkish (tr) Wikipedias, names of languages that start with the letter ⟨I⟩, are shown with a dotted I, e.g. "İtaliano" instead of "Italiano".
This happens because these two languages capitalize ⟨i⟩ as ⟨İ⟩ and not as ⟨I⟩ as most other Latin-script languages do.
Names of languages in the interlanguage links list are capitalized using ucfirst in the Language class. It probably runs using the az or tr locales, but it must use the locale that is relevant for the language the name of which is being capitalized.
Another option is to remove capitalization entirely, and just use the name from Names.php as-is. It already includes capitalization for language names that need it, like English.