I think there are a couple of minor bugs in the plugin at the moment. The description is actually only intended to display in the month grid when you’re on a phone breakpoint. (And there it’s not actually displaying the month as a grid, but collapsing to a list.) So there’s a CSS issue that is causing the phone-only descriptions to show in the grid.
As noted in the admin support page, the description length setting is only supported by the list view, but maybe I need to make the admin elements for that feature work a bit better.
There are also some CSS issues with the relative sizes of the text. I’ll try to address these in the next update. In the meantime, you can make the descriptions italic by adding this bit of CSS in Appearance > Customize > Additional CSS:
.ics-calendar .events .eventdesc, .ics-calendar .events .location { font-style: italic; }
Version 2.0.3 includes some fixes to the CSS issues.
My intention with the design was that the descriptions should not be displayed in the calendar grid itself, but only as a tooltip on hover, and on the phone breakpoint; it was a bug in the CSS that it was showing at all times.
There is a note in the changelog for version 2.0.2 that indicates a workaround if you prefer to have the descriptions shown in the grid.
