Dear GMaes3,
Good day! Thank you for posting to the Microsoft Community. We are happy to assist you.
I’m sorry to hear about the problem you are experiencing and for the inconvenience it has caused. We deeply understand the situation and apologize for it.
Regarding your current issue, we have recently received similar reports from users in this community about the copy plan option missing in the New Planner.
I have checked, and unfortunately, there is no service incident at the moment. Since this issue has affected multiple users, it could be a temporary server issue. Given that this seems to be a server-level problem, I sincerely recommend that you create a support ticket with Microsoft Support directly by following the steps provided in this link: Get support - Microsoft 365 admin | Microsoft Learn
If you are not an admin, you can contact your admin to contact Microsoft support. You can look for the way to find your admin through this link: How do I find my Microsoft 365 admin? - Microsoft Support
In the meantime, I would like to make a summary on this issue. This will also help other community members to find solution much easier of they come across the same situation:
Issue Description:
Planner - Copy Page Missing
Environment:
Planner
Suggestion:
Since, we are currently experiencing a server-level issue, which needs to be investigated and fixed by the development team.
I would sincerely suggest you report the issue to our development team by raising a support ticket from the Office 365 admin center, where the appropriate team will assist you.
You can also report the issue by going to **** https://planner.cloud.microsoft > Feedback icon (top right) > I don't like something. The more reports they receive from different customers, the more likely they will be able to find something affects users in common, do investigation and fix it soon.

Please accept my Apologies and I do feel regret for not resolving the problem and redirecting you to the related development team but the fix to your concern can be find out through the background logs. Please note that I have also reported the issue from my end.
We are redirecting you to the proper one to solve the issue. That’s why we suggest you report to our development so that, they will help you as soon as possible.
Sincerely,
Ralph Chawatama | Microsoft Community Moderator