Am a keen follower of Microsoft's SharePoint Blog and proud to provide this direct from the Microsoft Tech Community:

SharePoint OOB Approval workflows are missing on SharePoint online site even after activatingreactivating the “Workflows” site collection feature.

 

Missing workflow templates: 

Publishing Approval

Approval – SharePoint 2010 

Collect feedback – SharePoint 2010

Collect Signatures – SharePoint 2010

 

Issue:

SharePoint OOB Approval workflows are missing on SharePoint online site even after activatingreactivating the “Workflows” site collection feature.

 

We just see below templates,

image.png

And in SharePoint designer, Wfpub contents are shown as folder and NOT as a library.

image.png

 

Background:

  • Workflows feature depends on OffWfCommon (c9c9515d-e4e2-4001-9050-74f980f93160). 
  • OffWfCommon generates wfpub library when activated.
  • Workflows features will deploy globally reusable workflows in wfpub when activated.
Initially activating Workflows means activating OffWfCommon and Workflows at the same time.
So, OffWfCommon will generate wfpub library and Workflows will deploy those workflows.
 
But unfortunately from the 2nd time, activation of Workflows feature only means the Workflows feature itself. This is because OffWfCommon remains activated. So it works like this.
  • Workflows features will deploy globally reusable workflows in wfpub when activated…
    But wfpub is not there. So empty folders are generated to cover up.

Expected:

 image.png

Actual:
image.png

 

Resolution:

-Deactivate the “Workflows” site collection feature.

-Remove Wfpub folder from “_catalogs” – SharePoint designer

-Toggle the OffWfCommon feature

  • Connect to PNP site collection and run below cmd,

      Disable-PnPFeature -Identity c9c9515d-e4e2-4001-9050-74f980f93160 -Scope Site

      Enable-PnPFeature -Identity c9c9515d-e4e2-4001-9050-74f980f93160 -Scope Site
-Now activate the “workflows” feature from UI should bring back the missing OOB workflows.

The above is kindly provided by the Microsoft Tech Community!