[Lucas]

You are correct that the future task for a repeating task does not get created until the current task is completed. That is why, before you click the current task as completed, you won't see the future task.

Task groups repeat in a way that you might not expect. That is, if you set the task group as repeating, it doesn't create a new future group until the group itself is marked as completed. Then, the future group, with the tasks in it, will be created.

It sounds to me like you would be better off setting the task itself as repeating monthly. I have that arrangement myself.