Hi Ryan Rohm •,
Welcome to Microsoft Q&A forum.
As I understand, you are experiencing Redis Access Policies keys are case sensitive but are forced lowercase in azure portal.
This is strange and not expected, could you please try to add access policy using Azure CLI
https://learn.microsoft.com/en-us/cli/azure/redis/access-policy?view=azure-cli-latest
and see if this helps.
Awaiting your reply. Thanks