Unable to select "Worker can select manager when creating document"

Summary

Unable to select "Worker can select manager when creating document"

Content

Hi,

We are in 19B and Iam trying to create a new performance document type and a performance template such that the worker should be able to select a manager of their choice.

For some reason, the option "Worker can select manager when creating document" seems to be grayed out while creating a new  'Performance Document Type' .

Hoping that when I create a new performance template, using this same performance document type, I may be able to select the option here, but the option is grayed out here as well.