The first thing is to confirm – is this happening on the desktop/laptop version of Google Calendar or on the mobile app version?
If it is the mobile app then check this article for Google Task issues and this article for Google Keep issues.
If this is happening on the desktop/laptop then keep reading for the quick and easy (I promise!) solution.
Check the checkbox
Essentially what I mean here is that at some point you’ve probably accidentally de-selected the view checkbox on the home screen. Simply click on the checkbox again to view your Reminders and/or Tasks:
You’ll be able to tell that you’ve updated Google Calendar correctly if you can not only see your Reminders and Tasks again, but you can also create Reminders and Tasks as well. If the boxes aren’t checked, then your only option when clicking on the Create button will be as seen in this screenshot (if you’re using the free version of Google Calendar).
If you’re using Google Workspace but don’t have Reminders and/or Tasks checked, then you’ll see these options when you click on the Create button:
And that’s it!
I told you it was simple, but sometimes the simplest things are the most annoying to fix!