Why can’t you use your Pokémon in the Catch Cup in Pokémon Go?

gamepur.com:

The Catch Cup is a limited-time event in that you can choose to participate in Pokémon Go. In it, you’ll have the chance to use a small pool of Pokémon from your roster in this PvP event against other players. However, for some, when they attempt to jump into the Catch Cup, all of their Pokémon are blanked out. Why can’t you use your Pokémon in the Catch Cup in Pokémon Go?

Typically, everyone would be limited to using Pokémon that they’ve caught following Tuesday, March 29 at 8 PM GMT will be available in the event. If you’re trying to use a team that was caught before this date, they won’t be available. Any Pokémon caught before this time will be blanked out and available. Some players are encountering these issues with Pokémon they’ve recently caught, and if you are, we recommend you restart your Pokémon Go application.

With the event starting on March 29, you’ll want to make sure you use only recently caught Pokémon. A handful of players have shared they continually run into issues with the Catch Cup, regardless of restarting the application or catching new Pokémon for their team. If these issues persist, we imagine Niantic’s team will reach out to the community to address this issue with a quick patch.