Addition of calendar produced ghosting

The site is northeastspca.org. The page is Events. I inserted a calendar with a placeholder that has been working well, until lately. Now on the page you’ll see some ghosting of the calendar. It’s an overlap. It is happening on the larger and mobile variant.
I’ve done the usual clearing cache, and running as adm. I will probably clean this up by deleting the present, and starting the calendar again solving the problem; but I would like to know the cause. Thanks all for suggestions.

-Bill

Think I solved this one. In the placeholder dialogue box I put code in the Head, and Body. I should have placed code in the body only. (I think)

w

Your are correct Bill, display items you want positioned are added to the Placeholder Body.

Acorn