I think it is fatigue as addressed in this thread and this.
If you look at the games he gets it going on offense it's when he gets some early touches that go as hoped. Lots of examples of this. Hope he works through this
If it is fatigue, when he is this young and it is this early in the season, we better dump him ASAP.
I cannot see how it could possibly be physical fatigue. He is too young and too strong, the season is early.
I think it is frustration, largely will lack of whistles in his favor from the refs. Could be frustration with lack of performance, partly brought on by frustration with lack of coaching, or support from coaching? He did not look exactly thrilled to see Ty on the sideline when he came out of the game.