maxReceivedMessageSize property performing different across environments

Question

We have three identical test environments set up. On each of these environments, we have an application that, when you hit a submit button, grabs text from a form and turns it into an XML and then sends it to a WCF to be inserted into our Oracle database (version 11g). Each application has an identical app.config (aside from server-specific config keys: <add key="FolderPath" value="\\[server name]\Folder"/>) that has maxReceivedMessageSize="65536".

Here's the problem, in one environment when I try to submit the XML I get that error everyone gets: Maximum message size quota for incoming messages(65536) has been exceeded, but in the other two environments it works just fine when I submit the exact same XML. I can't figure out for the life of me why this is happening.

Here's what I've tried already in the order I tried it:

1. Stop and started the appPool for this application's WCF in IIS.
2. Refreshed the site for this application's WCF in IIS.
3. Restarted the server that this application's WCF resides on.
4. Tried submitting various sizes of data in XML form.
5. Deleted the site from IIS and redeployed the WCF.
6. Restarted the server again after the deployment.

Now, increasing maxReceivedMessageSize does fix the problem, I'm just wondering why I don't have to do this in the other environments.