It is not possible to remove a Resource Manager from a Resource via XOG.
Steps to Reproduce:
Expected Results: Resource Manager is now null (blank).
Actual Results: Resource Manager still has the previous value.
Release : 16.0.3
DE67040
Engineering has reviewed this issue and this will not be fixed for now. The fix can be prioritized by bringing this to Product Management for a future Clarity version.
Workaround:
Use the REST API instead:
PATCH - <server>/ppm/rest/v1/resources/<resourceId>
Body (JSON):
{
"manager": null
}