Calendar display anomoly

Our events calendar has two types of events:
Members only evnets – free to members.
Non Members events – a fee must be paid to book these.
(They’re physically the same event, but from a bookings perepective they’re configured as seperate events.

If you navigate to our event calendar from the site’s dropdown menus, (Members Only > Bookings) only the Non-Members events are visible.
If you view all the events for any given date (clicking on the date number) both Members and Non Members events are displayed.
Depending how you go back to the calendar, you get different results:
– If you go <back> via the browser’s controls, both events are now visible in the calendar.
– If you click on the calendar icon and then on <Month>, both events are now visible in the calendar.
– If you navigate back via the site’s dropdown menus, (Members Only > Bookings), only the Non-Members events are visible.

Any idea how to make the events display consistently?

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