The sub presentation is synced to CRM as a normal presentation, but not works as a sub presentation.
This may occur if the sub presentation binder is added to the presentation binder directly in Vault.
1. The Vault Owner or System Admin removes the sub presentation binder out of the presentation binder firstly.
2. Then Vault Owner or System Admin adds the sub presentation to the Related Sub Presentation section of the appropriate slide.
3. The CRM System Admin implement sync from CRM Side.