You lost connection to your opponent. Rivals and Champions

Hi everyone and EA Support team,

I am writing to report a game-breaking bug that prevents me from entering matches whenever specific card types are used in my squad active setup.

I have conducted thorough testing with multiple squad configurations to narrow down the cause of this issue. Here are the details and all the methods I have tested:

The Issue:

Whenever I include Special Cards (e.g., promo items, special event cards) or Evolution Cards in my active lineup, squad, or bench, the game throws an error and disconnects/prevents me from starting a match. Currently, the game only allows me to play if I use a full lineup of standard Base Gold Cards. Playing with a basic gold squad at this stage of the game makes competitive modes unplayable.

Squad Setup Methods Tested (All Resulted in the Error):

Special/Evo cards in Starting 11 + Bronze cards on the bench: Error persists.

Special/Evo cards in Starting 11 + Special cards on the bench/reserves: Error persists.

Full Base Gold Starting 11 + Special/Evo cards placed on the Bench or Reserves: Error persists.

Moving Special/Evo cards out of the Starting 11 into the Reserves entirely: Error persists as long as they exist anywhere within the squad structure.

The Only Working Setup:

100% Base Gold Squad (Starting 11, Bench, and Reserves): The match launches without any errors.

It is clear that the trigger is the presence of non-base Gold items (specifically Evolution and Special event cards) within the active 23-player squad file, regardless of whether they are starting, benched, or reserved.

Please look into this squad validation / server sync issue as soon as possible, as relying solely on base gold cards severely impacts the gameplay experience.

Thank you.