Shiny Koraidon code not working after a communication error

I was fortunate enough to have gone to my local GameStop right after they opened so I was able to get my hands on one code card. I just went to redeem it in my main Violet playthrough. I typed in the code and as soon as I clicked the Koraidon gift I got a communication error and now when I enter the code it says it has been claimed already. It did not receive the gift. I checked for Koraidon in my boxes in case it just skipped the animation, but there is nothing. Now I just have a dead code card. Has anyone else experienced this glitch?