Seems like he has trouble adapting to WEC, here is a link to interview of Ogier with Belgian RTBF during the Spa WEC weekend where he goes in great detail about the difference between WEC and WRC

What's the most difficult?

"The use of tires is something very sensitive, even more so than with us in rallying. I don't have the experience, so I don't have the understanding yet. I had made a visualization of the car perhaps even better than it is, I tend to expect a little too much from the car and therefore over-drive it. It's one of the things in which I'm improving and where I still have to improve with the short time I have on the track. This is clearly a parameter that I had not anticipated."
www.rtbf.be/article/sebastien-ogier-un-homme-heureux-10990222