Trying to book seat reservations from Paris to Tours or St Pierre Des Corps in April 2026

Hi

I’m trying to make a seat reservation from  Paris to Tours or St Pierre Des Corps in April 2026. When going through the Eurail seat reservation system, every train from April 5th to 11th says “No price results were found. Pass holder reservations may be sold out for this connection, but there are other ways to check for available seats—more info below our timetable.” Surely not every seat for the whole week is booked out already? Or do they release seats  not until 2026 for April?

Or is the system not working?

Any answers welcome. 

Thanks

Jon