Mac Reminders - Click Calendar Days Removes Reminders

This issue occurs on the Mac OS version of Apple's "Reminders" application. It started happening while using Yosemite and now continues to be a problem on El Capitan. Quitting Reminders and relaunching the application only allows it to work briefly. I am using a 2012 MacBook Pro.

1. Activate or launch Apple's Reminders application

In the lower-left corner, there is a Calendar with click-able numbers (calendar days). On days where you have reminders scheduled, there are dots under them. If you click the number with a dot, the application will load a list of reminders for that day.

2. Click these calendar day numbers until the all the "dots" under the calendar day numbers disappear. You'll notice that the events will no longer list when you click that day.

Not sure how I am suppose to fix this kind of corruption. Any ideas or suggestions would be appreciated. The images below show all the dots I have for May 2016 and then they magically disappear when I click on a different day. Quitting and launching the app again brings them back until I click the calendar day numbers again.

*** Also, I just noticed that the "disappeared dots" calendar is missing day "31" of May 2016... something odd is happening. Also day "1" should be a Sunday but becomes a Wednesday in the 2nd image.

BEFORE: THE "DOTS" INDICATING A REMINDER EVENT

AFTER: CLICKING CALENDAR DAYS REMOVES ALL REMINDER EVENTS