Easy boulder on the same block as Travaux Forestiers 6c+. You can find it close by Le Presse-Banane 4-. I found it a bit harder, almost grade 5 because from the sitstart position in one move to the edge is to far away. Using the sloper is more technical for me.
Rain sucks, but broken holds suck even more. Remember, never climb on wet rock in Fontainebleau.
The sandstone becomes brittle, and pulling on it will ruin classic problems. Drying it doesn't help, because it's still wet and weak inside.
All you can do is wait for better conditions.