Android : Handle OAuth callback using intent-filter

So I changed my approach to use a custom scheme, rather than a web URL and it now all works as expected.

So my callback URL is:
X://callback

and my intent-filter is:

<intent-filter>
    <action android:name="android.intent.action.VIEW"></action> 
    <category android:name="android.intent.category.DEFAULT"></category> 
    <category android:name="android.intent.category.BROWSABLE"></category> 
    <data android:scheme="X"></data> 
</intent-filter>

where X is the name of my customer scheme.