The crank on my 2016 Giant XTC Advanced (Shimano XT components) is slipping relative to the large chainring but not the small chainring. In searching for reasons many of the answers focus on chain skipping but do not believe this is the case.
I positioned the front wheel against a wall and then marked the chain and large chainring so I could see whether the chain was skipping relative to the large chain ring. I applied pressure on the crank using only my hand and the crank slipped. The marks on the large chainring and chain were still aligned and still in the same position so no chain skipping and no movement of the freehub.
I do not have the same issue when riding in the small chain ring and there is no movement between the large and small chainrings.
Any help is much appreciated.