No, you’re correct.Didn't Sunak (i) lose to Truss in a vote by the party membership, then (ii) became party leader (and PM) when Truss quit as he was unopposed so there was no vote?
I could be wrong; we've had so many PMs in the last few years its hard to keep track tbh
Cameron won against David Davies
May won when Andrea Leadsom withdrew
Johnson beat Hunt
Truss beat Sunak
Sunak was unopposed in taking over from Truss