This sitstart boulder is on right of orange n°6 and (La Véronique 3) on the left of light blue n°28 bis (La Vespasienne). You start at the big flake/crack and exit directly above by a mantle.
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.