There have been some reports recently about the ES not crawling the entire content of a document.
Unfortunately this issue is caused by a bug in our software. We have now created a first stage fix that helps in most of the cases, but not all.
Thus that is experiencing this issue may install this first stage fix manually by:
From the admin panel then go to Software updates -> Advanced and update it manually.
A second, more thorough fix that will solve this for all files is also on the whey but will require more testing before it can be released.