Hello again,
I compared the unformated version of the ENREF with one from the same author (that is working) and there are no differences. I even selected the option to see all field codes, and even there there were no differences.
I went through the clean up proces you suggested, but the problem still remains on the same exact references. I even copied the version that had the field codes removed and the unformated citations to a new word document, and then reformated, but the problem still remains.
Unfortubatly the link you sent me does not work, it might be because I am from Portugal.
I have noticed though that if I delete everything before the literature review (which is just plain text, one image, and some references) the number of ENREF occurences decreases by 1 (from 46 to 45).