Nitantic hasn’t responded so I’ll ask here - Problems with redeeming for Raikou?

Last saturday (during the first part of the Eevee event), the event started while my mom was trying to catch Raikou as the event started. Raikou errored out, because it wouldn't stay in the ball, and when she went to try again it presented her with a blank screen. She was able to recover all items related to the event, and as far as she remembers there were no other pokemon tied to the reward pick up. Since then, the reward refuses to accept and any time she attempts to collect Raikou from the reward, it gives her a blank screen with no way to get out of it. The clouds at the top indicating the weather can move, but she has to restart the game to get out of it.

The rest of the game plays as normal, even with her rewards still registering - however the game treats it like she hasn't redeemed Raikou and won’t allow her to get any other rewards.

Has anyone else had this problem or knows how to get it to let her catch Raikou? It would be a great help for any tips to fix the problem. If it matters, she has an iphone X, and has tried uninstalling and reinstalling the game with no luck in fixing the issue.

Thank you for your help!