Hi!

Don't forget that with Pro account, you can contact me by email (sometimes i don't check forum for 2 or 3 days, but try to answer email for Pro user each day )

About your problem : it's a not well module class suffix settings.

See info here : docs.joomla.org/Using_Class_Suffixes

You need a "space" before your class suffix name.

So, with the space, you load correctly the class css for the calendar.

But, as many users do this error, i will add a default space, to prevent not loading of css class used by script files to make arrow and tooltip working.
This is not the core way of doing (as it is in current version of iC calendar), but by adding always a space in my code, this will prevent errors in adding a class which make the calendar not working as expected.