Did prophet Mohammed PBUH told we have to read Qur'an only in Arabic?
The Quran was revealed in Arabic and no other language.
In Surah Yosef 12:2 =
Indeed, We have sent it down as an Arabic Quran that you may understand.
So only the Arabic Quran is considered Quran and must be recited in Arabic.
One of the miracles of the Quran is in the Arabic language. No man and jinn can create something like it.