There could be two reasons why asset's that are specified on the Service Contract are not pulling through to the task.
When a task is created and it's Service Contracts are added, any changes made to the property will cause the task/s need to be updated.
The task needs to be updated.
If you have added more asset's to the property or have specified more asset's to be serviced on the Service, a button will appear under the 'Servicing/Actions' tab on the task.
This blue button with say 'Re-apply sub-tasks'.
The asset's on your property haven't been assigned a contractor.
If the asset's in question haven't been assigned a contractor, then you need to either assign the contractor as yourself OR you need to change the preferences on your service.
If the contractor isn't your own company, then you need to do the following:
Step 1: Under the Work tab on your TASK, click the service contract in question.
Step 2: When you are in the Service Contract page, click the link to the Service (See below).
Step 3: Once you are on the Service page, click Edit Service.
Step 4: Go to the Servicing section and click Subcontracted assets = Yes
Subcontracted asset's: yes = Your assets are contracted by your company and someone else
Subcontracted asset's: no = Your assets are contracted only by your company
Subcontracted asset's: only = Your assets are only contracted by another company
Step 5: Save
Step 6: Go back to Servicing/Actions tab on your task and click Re-apply sub tasks