making a reservation with Siri

Is it no longer possible to make a reservation at a restaurant with Siri? I have open table installed, running and I'm logged in but when ever I try making a reservation, Siri tells me that he can't book a table right now but has found one place matching the restaurant I want to make a reservation at.
Has anyone got this to work? In the past, its always been a hit and miss but now, I can't get it to work at all.