Some calendar events not visible on iphone but visible in iCloud (Web)

My school provides a custom iCal file that makes up my classes for the year. I have imported this .ICS file into iCal (to an iCloud calandar) and it works fine on iCal and when I log into iCloud.com, it looks fine as well. However, when I open Calandar on my iPhone (7.0.3), these items are missing. I see the calandar and can add items to it (which reflect on iCal) but the items from the .ICS file never show up on the phone.

I've shared the file through DropBox: https://www.dropbox.com/s/uetchw2ikj4bwnx/Classes.ics

Any help would be appreciated.

Cheers.