CRM 365 Ignoring Default value on Opportunity Models

Hi All

*CRM 365, On-Premise, 8.2.0.749*

I have a new challenge, this time with Opportunity models where CRM ignores 2 default values of fields.

On a Opportunity, via the subnavigation we go to the associated Opportunity models screen.
When we try to add a new Opportunity model, the Opportunity model form opens and two fields ignore defaults set on field detail level

• 'Select product' is set to "Write-in" while the default value is set to "Existing product"
• 'Pricing' is set to "Override Price" while the default value is set to "Use Default"

As a workaround I tried to create a businessrule which sets the values to what I want them to be, but this either has no effect or is overwritten by this behavior too..

Any ideas?