How to Change HCM Group membership Start Date for a group/single Employee?

Summary:

Hello OTL Community and Experts,

We have an issue where the membership start date of an Overtime HCM group, changed to a recent date automatically for a large number of users in PROD due to the impact of some Process.

We are not sure on what process/steps changed this membership start date of the group.

Because of this, a large group of employees are not able to submit Overtime in their Time Card for a period, that is one or two weeks prior to the new Membership start date.

To understand this or to have a quick workaround, I'm trying to recreate the error/issue in Dev/lower instance.