iPhone calendar with multiple calendars - only one is selected to display

I have the default iOS Calendar app setup with multiple calendar accounts - iCloud, Exchange and Google. Whenever I open the app, it shows only one of the calendars. I can select them, select holidays and birthdays, then close the config, after which all calendar events are shown. Then if I close the app, reopen and change to a different date, all the events for the other calendars disappear. This is not workable.

What can I do to get all the calendars displayed, and have the setting saved properly?

Under Settings>Calendar

Verify accounts connected to device

On the Calendar app, zoom out and then click on calendars on the bottom

Enable Accounts That you desire to be synchronized with your calendar