So if you are one of few that are using IE11 and SharePoint 2013 you have probably noticed many corruptions and misbehaves in UI. So far I have discovered the following problems:
- Calendar web part is extremely corrupted
- You will click Settings > Edit Page, Pages will not enter edit mode.
- Web Part Properties cannot be modified.
So until we get official CU or SP from SharePoint team, run your sites in compatibility mode.
- Click Compatibility View Settings in Settings
- Click Add to add the current SharePoint site to your list.