fix: custom routes not working for nested pages from layers

[BobbieGoede]

🔗 Linked issue

• Nested Routes are not created with pages options for layers #2412

❓ Type of change

• 📖 Documentation (updates to the documentation or readme)
• 🐞 Bug fix (a non-breaking change that fixes an issue)
• 👌 Enhancement (improving an existing functionality like performance)
• ✨ New feature (a non-breaking change that adds functionality)
• ⚠️ Breaking change (fix or feature that would cause existing functionality to change)

📚 Description

This should resolve #2412, includes tests.

Took longer than I should have to fix this, so easy to overlook a missing param 🤦‍♂️..

📝 Checklist

• I have linked an issue or discussion.
• I have updated the documentation accordingly.