Question regarding creating a template_groups plugin

I have a pile of CMPS portal templates, that are prefixed with adv_portal.

I created a new plugin in vB/General Admin/template_groups with the following:

$only['adv_portal'] = 'Portal Custom';

And it only half works. It's grouping the templates created by the parent product, but not grouping any custom templates I've created afterwards.

What am I missing to get the plugin to group the custom templates as well?

Screeny attached to show what I'm talking about. Thanks.

[Logician]

It should be because of 2 reasons: (either or both)
a) While creating your template make sure you set Product as the product name of the other templates.
b) Create your template in MASTER style, not in child styles (Requires you enable debug mode)

[craiovaforum]

How do you set the product name while creating a template?

[BSMedia]

I think this is also a problem with vBAdvanced, as their templates are already grouped, except when creating new ones with their prefix.

I'm not sure how to fix it honestly, but i've had the same problem for a while thats been bugging me.