Has it been authentically reported that the Messenger of Allah (peace be upon him) met the Jinn (creatures created from fire)?
Yes, this has been confirmed in an authentic Hadith. The Prophet (peace be upon him) told the Sahabah (his Companions) about this meeting and showed them the traces left by the Jinn. You may refer to the Tafsir (Qur'an Exegesis) of (Part No. 3; Page No. 372)
Ibn Kathir (may Allah be merciful to him) regarding the saying of Allah (Exalted be He) in Surah Al-Ahqaf,
And (remember) when We sent towards you (Muhammad صلى الله عليه وسلم) a group (three to ten persons) of the jinn, (quietly) listening to the Qur’ân.
As well as Surah Al-Rahman and Surah Al-Jinn. In the Tafsir you will find an elaborate answer to your question.May Allah grant us success. May peace and blessings be upon our Prophet Muhammad, his family, and Companions.