fix(model): display subform when model is already selected on page reload

[MyvTsv]

• I have performed a self-review of my code.
• I have added tests (when available) that prove my fix is effective or that my feature works.
• I have updated the CHANGELOG with a short functional description of the fix or new feature.
• This change requires a documentation update.

Description

• It fixes !41257
• When a template is selected from the drop-down list used to select a template, a specific form is displayed below.

However, after reloading the page, the template remains selected in the drop-down list but the associated form is no longer displayed.

Screenshots (if appropriate):

Before:

After:

[stonebuzz]

Can you adapt CHANGELOG.md