I spoke to a bizjet pilot today about this.
The issue is highlighted in this ridiculous post
He said this is spreading in France, but it appears to be boycotted by busy pilots who just tell the airport they don’t have the time to waste and who just want to arrange handling (if required) by email.
I am not completely stupid, but I have just counted 22 emails with Annecy airport trying to make this stupid website work and to check the resulting pricing. And I still never got a reply to the last question (what is the handling charge if operating on a weekend?).