Can't connect to web admin

[eshikafe]

Hello,
I can't access the ejabberd web admin page. It keeps throwing an unauthorized access error.
I am using the same docker-composer file in the README:

ejabberd:
  image: rroemhild/ejabberd
  ports:
    - 5222:5222
    - 5269:5269
    - 5280:5280
  environment:
    - ERLANG_NODE=ejabberd
    - XMPP_DOMAIN=example.com xyz.io
    - [email protected]
    - [email protected]:password4321 [email protected]

Web browser URL: https://x.x.0.3:5280/admin
password: password4321
username: "admin" or "[email protected]"

Output from the Erlang shell:

16:04:00.483 [warning] Access of <<"admin">> from <<"x.x.0.1">> failed with error: <<"inexistent-account">>
16:04:15.777 [warning] Access of <<"[email protected]">> from <<"x.x.0.1">> failed with error: <<"inexistent-account">>

"admin" is a registered user:

eausaig@ubu:~$ sudo docker exec 104f89555384 ejabberdctl registered_users example.com
admin

Any suggestion on how to fix this problem? Thanks.