Loki won the wizard tournament and became Sorcerer Supreme (shown in Doctor Strange #383). However, in Doctor Strange #385 this is said to have been a ruse, claimed by Zelma who thought she could reach his soul ("You reached into my soul, remember? Well, guess what, genius. That was a two-way street. I saw everything you were trying to keep from me. From us."). I highly doubt anything that comes from Loki, be it consciously or unconsciously shared.
So far, there are two options: Either Loki really was Sorcerer Supreme and just faked having it faked and was able to transfer the powers back to Stephen Strange (without anyone noticing), or it was as Doctor Strange #385 wanted us to believe and just a ruse. Let's assume the latter for now.
Then certain things don't make sense. He told everyone he was Sorcerer Supreme. He told Thor in Doctor Strange #381 and teleported them away instantaneously to help her stop an ice giant invasion of earth. He told his mother in Thor #704 with the Mangog in Asgardia's halls with an offer to send her "far enough away that the Mangog will have to search for a million years". He even told a cat in Unbeatable Squirrel Girl Vol. 2 #29 "Why am I creating illusions anyway? I'm the Sorcerer Supreme now, Mew! I can just summon people to fight for me!" and he does. I'm not sure how serious I am to take Unbeatable Squirrel Girl, but Loki is a little bit too convincing in his role. He has powers he shouldn't have. My 4th-wall-guess is that the writers of Doctor Strange really let their colleagues believe that Loki is Sorcerer Supreme, so that whatever they would come up with would look convincing.
Question: If Loki wasn't Sorcerer Supreme, how can the inconsistencies about that be explained?