Hanafis Admit Prophet (Sallallahu Alaihe Wasallam) Prayed 11 Rakat Taraweeh

In the classical Hanafi book of jurisprudence Maraqi al Falah it is mentioned

وصلاتها بالجماعة سنة كفايه لما ثبت أنه صلى الله عليه وسلم صلى بالجماعة إحدى عشرة ركعة بالوتر

Translation: And praying it (Taraweeh) in congregation is a collective Sunnah because it is proven from him (the Prophet Sallallahu alaihe wasallam) that he prayed in congregation eleven rak'at including Witr.

Reference: Maraqi al-Falah Page #159