Calendar displaying Bogota time

I plugged some events into a calendar, and some of the events show the time in Bogota time, and some show the time in Eastern time. However, all of them have eastern time selected as the preferred time zone. Why would it alternate and how can I change it so it does not display the time of meeting as Bogota time?

Example, the NIST webinar below is at 12pm Eastern time. But in the roll-up it displays Bogota time of 11:00am. ????? Anyone have a solution?