The 14:03 Lille - Lyon is now fully booked (see SNCF website). There would probably have been a 20€ seat available, since you were also able to book a normal ticket, but there's a long standing issue on the Eurail/Interrail site to show these 20€ seats, which are available after the 10€ seats have gone and until the train is fully booked.

What train(s) to Torino are you trying to book on on 21 April and for how many people? Please provide origin, destination, departure time per train, otherwise we have to guess what you're trying to do.

@Nanja @Marion do you have a fix date for the 20€ seat problem yet? It's really annoying.

@Nanja its not just annoying its expensive!  I have had to buy a ticket from SCNF at normal price for this and when I complain to Interail customer services there is no reply.

clearly as rvdbprgt says the tickets were available as I was able to buy!  another question is how do I get recourse for this?

I had the same problem with my Eurostar seat reservations which were apparently not released from the Interial system until I wrote 

@rvdborgt thanks for getting back to me 

in reply to your question I am looking to reserve the thursday 21st April 2022 15.41 Torina Porta Susa to Paris Gare de Lyon 

and 

Sunday 17th April 2022 11.11 - 19.15 Pordenone to Foligno (Venezia Mestre - Firenze) requires seat reservation that cannot be booked . for Firenze to Foligno N/A is next to seat reservation requirement.  does N/A mean Not Available or Not Applicable?  

same problem see below

It is always more helpful if you give as many details as you have. E.g. a screenshot of the problem.

21 April 15.41 Torina Porta Susa to Paris Gare de Lyon: "Seat reservation unavailable” - the most likely reason for this is no passholder seats left, especially since the module is showing available seats for the 17:38 service, which means there's no problem with the connection to the SNCF reservation system. Unfortunately, the international TGVs have a limited number passholder seats and there's no higher pass fare available until the train is full (and actually, most of the international TGV pass holder fares are already a rip-off).

17 April 11.11 - 19.15 Pordenone to Foligno: only Venice - Florence needs a reservation. Italian day trains are now best booked via ÖBB (using these steps). ÖBB don't need any pass number and don't charge booking fees.

ÖBB has only started recently to sell these reservations, so I hope this will be added in the next release of the app.