Hi!
Interestingly, I had a similar support case last week.
We copied the whole text into a new document and then it was ok (the h in http was hyperlinked again). We didn’t understand why. The following day the patron called me and told me that the error occured again after he stored the new document in Sharepoint. The original document was also stored in Sharepoint.
Where is you manuscript stored? Try to copy the text and insert it into a new document that you store on your harddrive. Does this fix the problem?
Best wishes
Jan Ove