Bubbles are blank

Updated to simple calendar 3.0.1 yesterday and now the bubbles on our grid calendar are blank as if printing in white on white. Viewing calendar in Internet Explorer 11 latest version. Updated to 3.0.2 today. Still the same. Note that on my Blackberry phone the bubbles look OK. Have tried both dark and light theme. Don’t know what else to do as I’m not a web developer. Here’s a link to the calendar: http://copsphotography.org/cops-events-calendarlisting/cops-calendar/.

Any suggestions?

https://ww.wp.xz.cn/plugins/google-calendar-events/