The website developer did as you suggested and said this:
Ok, I tried the things they suggested.
• I fixed the SSL mixed content warnings
• I disabled all the plugins except the calendar plugin – it made no difference.
• I reverted to a base WordPress theme (Twenty Eleven) – I’m sure if this “fixed” it, but it did display differently. Instead of having to click “next events” to get to June, June was just displaying on page 1.
Do you want to pass this on to the support ticket and see if they have a solution?
Otherwise, I’ll start looking for a new events plugin to switch to.
I need a solution or tell me that for whatever reason, the DIVI theme will not work with your calendar. Thanks!