Have you checked to see if the mast is centered? Use a halyard to measure the distance from the top of the mast to corresponding points on each side of the boat. If it’s not at least close, that might be the cause of your problem.
It would appear that most Jeanneaus have a tendency to list one way or another. Our 34.2 has a starboard list which still needs to be addressed having already put most of our heavier portable gear in the large port locker. Yes the mast is fitted correctly but with both water and fuel tanks full it still leans to starboard not helped by a large lump of concrete ballast that Jeanneau placed on the starboard side in the void behind the saloon cushions which short of tearing the boat apart, will remain there. Our temporary solution is to embark as much French wine as we can fit into the port locker and enjoy it through the season. The additional righting moment imparted by our list appears to ensure that our performance on starboard tack is markedly superior to that on port tack!