I add new team member in team but next day system delete

[beibei Mu]

I add team member in Opsgenie team, the member is added only untill the day at 8 PM.

After 8:02PM the system removes member I added. 

[Scot Wilson]

G'day Beibei,
I'm Scot from the Opsgenie Support team.

Mate, we're going to need you to raise a support ticket through https://support.atlassian.com/contact/ to investigate this issue for you, as we'll require details such as the email addresses of the affected users, your instance name, and a few other specifics.

We don't want you sharing these sorts of details through a community forum, so we'll be waiting for your support ticket.

Kind Regards,
Scot