question #2 Sahih Muslim 648g, Book 5, Hadith 304 : How should one treat prayers performed with an Imam who does not observe the prescribed prayer times?

I said to ‘Abdullah b. Samit: We say our Jumu’a prayer behind those rulers who defer the prayer. He (‘Abdullah b. Samit), struck. my thigh that I felt pain and said: I asked Abu Dharr about it, he struck my thigh and said: I asked the Messenger of Allah (ﷺ) about it. Upon this he said: Observe prayer at its prescribed time, and treat prayer along with them (along with those Imams who deter prayer) as Nafl. ‘Abdullah said: It was narrated to me that the Messenger of Allah (ﷺ) struck the thigh of Abd Dharr.