Hi Robert!
You don’t need to add any code, but it is possible that your theme is customizing the calendar templates.
Just to set expectations right, I do want to note that we are fairly limited in how much we can support custom development questions like this. That said, we do like helping out so let me try and help you with that.
Could you please check if inside your theme there is a folder named tribe-events? If so, then let me know which files and folders are in it. This way I can take a look and point you where to modify the templates to make them show the month navigation on top. Let me know about it.
Also, when coming back, could you please share with us your system info by following this guide > https://theeventscalendar.com/knowledgebase/sharing-sys-info/
Thanks,
Victor.