With Teams Manager, the team creation process becomes multifaceted, involving a requester and approver dynamic.
You, as a user, get to submit a team creation request based on a certain template, then the approver goes through the details of your request before giving the final approval for team creation.
This means that until the approver gives the green light for your team to be created, it will remain as a request.
Alternatively, your Teams Manager Admin might've restricted team creation outside of certain groups/individuals.
If the request is urgent, you could contact your organization's Teams Admin for more information regarding the matter.