Hi Monica,
Thanks for reaching out!
We are limited by our Support Policy in how we can assist with customizations, but I’d love to help point you in the right direction!
What theme are you using? If you switch to a default theme, like Twentyseventeen, do you see the same issue occur?
If not, I’d recommend starting off by playing around with the stylesheets and page templates that you are using, as they determine how much of the styling from your theme is pulled from in the calendar:
https://theeventscalendar.com/knowledgebase/stylesheets-and-page-templates/
Let me know how that goes!
Thanks,
Jaime