Can you please give us your zone, realm and guild name so we can investigate. Thanks in advance.
It's in our best interest to resolve this issue, but to be honest, each time we attempt to check some character which was reported as bugged, we either see that character is working properly on wow-heroes (no bugs, live data), or we get "internal server error" from API, on both our servers and our home IPs, using regular (no-authentication) request to avoid any problems with API keys - for example
/api/wow/character/someRealm/someToon . So it's not a problem with API key or banned IP address or any function.