Solved: Unable to Register Users Remotely

I'm running ejabberd 17.07 on Debian 9. I am using PostgresSQL as the DBMS. In order to initialize the database, I used /usr/lib/x86_64-linux-gnu/ejabberd-17.07/priv/sql/lite.sql as a baseline. I made a copy called "plite.sql" and edited the MySQL syntax so that it fit with PostgresSQL syntax. I removed "INTEGER PRIMARY KEY AUTOINCREMENT" (which is not supported by psql) and exchanged it for "SERIAL PRIMARY KEY" as well as removed the "UNSIGNED" qualifier from the timestamp columns. Once I did this, I was able to initialize the database.

I'm able to manually register users by using this command:
ejabberdctl register foo example.com Passw0rd

Once I register the user, I can successfully log in as the user and receive valid SSL certificates, so I know that my configuration is working up until that point. However, when I use a client such as coyim or pidgin, it does not allow me to register. I simply get these errors:

Registering a new user with pidgin:

From coyim, I get a different error:

I fear that my configuration file is messed up. I've coped it to pastebin and removed/replaced any sensitive data. Please help:
https://pastebin.com/09rSQDVm

Some notes: I'm using cloudflare for the domain with SRV records _xmpp-client._tcp.example.com and _xmpp-server._tcp.example.com pointing to the XMPP server. The A records point to the web server. I'm not sure if this is useful information or not.