Seat reservation between Barcelona and Paris June

Hi, I was buying the seat reservations for my trip in May and June, and it went fine except for my connection from Barcelona to Paris on June 5th.

Looking up all the connections for the day, it tells me that they can’t show me the price and it could be that it’s booked out and I should try later.

I asked a Train Station Center for help and they told me it could be that I am too soon and I should retry a few times but that doesn’t calm me enough.

Does anyone have a tip for me?

It‘s in more than two months so I hoped I would be early enough.

thanks

Luca