Custom Parameters not recording

I’m pushing custom field parameters using the recommended approach however the data is now appearing in the fields section under the expandable 'detail’s drop down on an individual contacts profile. I’ve setup the custom fields and enabled the ‘can update publicly’ etc.

I’ve tried hard coding the string into a static page but the MT code does not fire. If I place the standard code, it fires if the custom fields is not included.

Is this feature still working? Seems like it’s not accepting it.

mt(‘send’, ‘pageview’, {CustomName: ABCDE});