EventBridge Scheduler unexpected 409 response

Hi,

We are using EventBridge scheduler to invoke lambda functions that send push notifications to users. If a user takes certain actions, the schedule for the push notification will be created or change.

Currently, when we receive an action that should update the schedule, we delete the current schedule (userid as name) and attempt to re-create it with update parameters. This is done because we do not know if there is an existing schedule. However, we frequently receive 409 error responses when trying to create new schedules, despite immediately before receiving a 404 response when trying to delete the same schedule (indicating that it didn't exist). Any ideas why this might not work as expected?