I am trying to update a AAAA record using the request:

https://api-ipv6.dynu.com/nic/update?hostname=pidp11.curuvar.com&myipv6=2600:4040:f108:ee03::03&username=*******&password=********************************

I get a badauth error. I have no problem with the request:

https://api-ipv4.dynu.com/nic/update?location=IPv4Home&myip=193.208.13.11&username=*******&password=********************************

Both use the exact same username and password values.

I've double checked that the hostname exists.

I've tried the v6 address both as shown and with the colons percent-encoded.

No luck.

Any ideas or hints as to what I might be doing wrong would be appreciated.