Good evening Adrian and welcome to the Events Calendar Support forum!
Thank you for reaching out to us. We are sorry to hear about the Events Calendar widget not displaying properly on that specific page.
We will gladly try to assist you on this topic.
Good job on troubleshooting the theme conflict as well.
The reason why the Widget is displaying weirdly on the second link is because that widget is receiving the following CSS classes: class=”tribe-mini-calendar-event event-0 first last “. More specifically, the .first class is the culprit since it forces a height of 30px.
On the first link you provided, the classes attributed to the widget are: class”tribe-mini-calendar-event event–1 last”
So I guess that if you could remove the .first class from the widget on the problematic page or make a CSS exception for it, it will come back to normal.
Let me know if that helps.
Have a great weekend!
Geoff B.