Template Variable value can be edited in next step of creating an Page using template

After moving to next step of creating a page. Specified value of variable still can be edited.

Steps to reproduce

1. Create a new template in Confluence (refer pic 1)
2. Add two variables to Template

• Work Product which has 3 properties: Component, Component & Product, Product
• KPI Scheme which has 6 properties.

1. Create a new page using the template (refer pic 2)
2. Select values for each box
3. Click Next>>

Result
After moving to nextstep, User can edit value of Work Product, KPI Scheme field. (refer pic 3)

Expected Result
User can't edit the value of Work Product, KPI Scheme field cause they're set in first step, they're value of variables