Time zone anomalies between Calendar times and reminder times

Hello:

I travel a lot internationally, and I constantly have screw-ups in my Mac Calendar app with time zones.

I thought I more or less had this figured out with workarounds, but now a new problem has arisen.

The times of my events in the pop-up reminders are for a different time zone than the times in the Calendar. What causes this? How can I stop this from happening?

Thank you.