Overview:
A workflow contains parallel review tasks. All the review tasks are approved, but the workflow task assignee of MA Director Review receives the three same tasks (shown in the diagram below).

Root Cause:
When the Vault admin creates parallel steps in a workflow, the Join step re-connects these branches and enforces that all parallel tasks are completed or canceled before the workflow advances to the next step. In this case, there is no Join step after all parallel tasks.
Solution:
A Vault admin needs to create the Join step and set it as the next step for all parallel tasks.
Related Documentation:
Vault Help Documentation: Join Steps