Increased PHP Memory and Calendar is still not working

I received this notification-
CSS compilation failed because you don’t have enough free memory (a minimum of 24M is needed). Your calendar will not render or function properly without CSS. Please read this article to learn how to increase your PHP memory limit.

I increased the PHP memory to 512M and the problem has not resolved. Here is the page with the calendar- https://www.otrtplayschool.com/calendar/

What do I need to do? Thanks!