Overview
A Job Task Type is assigned once per job, not once per service (see How to Create a Workflow Task in the Task Builder), so by default its sequence numbers apply across the whole job.
Example: Sequence #1 has Edit Photos and Edit Video; Sequence #2 has QC Photos and QC Video.
Off (default): QC Photos waits for both Edit Photos and Edit Video, even though it only shares a service with Edit Photos.
On: QC Photos unlocks as soon as Edit Photos is done, regardless of Edit Video's status.
How to turn on Shared-Service Job Gating
Go to Settings → Task Builder.
Click Settings (top right).
Turn on Shared-Service Job Gating.
Click Save Changes.
Notes
This setting is off by default.
This is a global setting — it applies to all Job Tasks on the account.
This does not change Service Task behavior, which already unlocks independently per service. See How to Create a Workflow Task in the Task Builder.