GCal incomplete booking informations

Hi there!

When someone book a date on my website, he selects (1) a place, (2) a provider, (3) a service and (4) a date.
In my GCal, all the infos are messed up - provider_location and provider are missing (among other bugs). How could we resolve that please?

I opened access to site in order you to check what could be wrong

Thanks a lot!