If you're having this issue it is likely because you connected your calendar/events to us via Cronofy.
You can check this by going to your connections page and taking a look at how we are connected to your calendar. For example, In my example, I connected via Cronofy:
Cronofy is great because it is an easy way for us to sync with your events. The downside is it only lets us access your events 6 months into the future.
If you would like to have all your events on your Events Calendar, then you need to connect us to your calendar/events via what is called an .ICS feed.
I fully appreciate you've probably never heard of this term before, but I promise it is really easy. We've written full guides to help you through every step of the way: