Losing all past entries in Calendar

Hi, I noticed today that all my past entries in Calendar are missing. This includes the entries set for specific times and the all day events that I entered. There are some all day events left, but they are the automatic ones like public holidays.

I am using a MacBook Pro running Sierra. And I have the Apple Calendar synchronized with Google Calendar on my Samsung phone.

The entries still seem to be all there on Google Calendar. When I make a new entry on Apple's Calendar then it synchs to Google Calendar on my Samsung without a problem. And visa versa. And if I just move one of the entries in the Google Calendar it then shows up on Apple Calendar on the laptop.

However, just Refreshing either, or both of the Calendars does not have any effect.

As I side note, because I am travelling in remote areas, the other day GMail couldn't verify my sending address, so didn't allow some emails to go through and sent me an alert message. However, I verified that it was me and everything seemed to work again once I got into an area with better mobile coverage.

And as part of that Alert process, I was directed to a page saying I should remove access to some unsecure apps. In this process I did remove and old phone but nothing else, and I don't see why that should effect my Apple Calendar.

I make some entries on my phone in Google Calendar, but the bulk of the entries would have been made on the Macbook in Apple Calendar.

Any thoughts anyone?

Thanks,

John