If you have downloaded the Iron's fixtures to your phone, operated by E-Cal, in recent seasons there could be a duplication issue which results in the updates cancelling each other out when synchronised.
To correct this, please go to the Calendar part of the settings on your device or desktop, and then in the accounts section, remove the Scunthorpe United options from your 'subscribed calendars'.
Afterwards, click here to download and all the updated fixtures should enter your calendar and automatically alter if the details of the fixtures change again.