Membership Package and Missing Custom Fields in Add listing form

Hi all,

I would like to offer the following listing and membership combination which provides customers who add multiple listings with more enhancements and longer duration listings.
1. General Listing Package – FREE to everyone for single listing .e.g. one-off listings
2. Premium Listing Package – FREE enhanced listings to Membership Package subscribers with multiple listings
3. Membership Package (linked to Premium Listing) – FREE package for multiple listing customers

I have created these 3 but the submit listing form for ‘Membership Package’ subscribers (linked to Premium Listing Package) excludes ALL custom fields I’ve created for listings. When I switch the ‘Submission Package’ settings back to ‘1. General Listing Package’, I can then see all custom fields in the listing submission form.
Have I missed a flag/ switch which associates the custom fields to specific listing packages?
Screenshot 1 = Membership Package with General Listing shows custom fields in submission form
Screenshot 2 = Membership Package with Premium Listing shows custom fields missing in submission form
Am I doing something else wrong?
Any help – as always, is greatly appreciated.