The issue does not seem to happen on refreshing the page — only when navigating to it from the calendar, or directly proceeding an edit. Although refreshing does not fix the problem as described in “SIDEPROBLEM” below.
Example
SIDEPROBLEM: on the Events Calendar homepage, this same day appears as Thursday… or Saturday… or Sunday in the Calendar, or the topic button that you can access from it — the association between days and positions in the calendar seems random.
To second the issue
It looks like it’s related to ‘Start Week On’ being set to another day than Sunday.
Changing it to Saturday or Friday causes the calendar issue, and causes the ‘Start Week On’ drop-down showing the wrong days as options (but corrects itself once a day is selected).
We are also having an issue where the calendar is unresponsive on mobile - users are unable to click/view dates
I’m struggling to find the “Start Week On” setting, I remember seeing it before, but it’s not coming up in the plugin settings, or the category settings.