The result of a search for Spanish terms seems to be dependent on the interface language used in L4. This was posted on the "Español" forum but got no attention from Logos representatives, I'm posting it here since it is not a language issue but an application issue.
For example, when the interface language for L4 is set to Spanish, a search in RV60 (Spanish Bible version similar to the KJV) for the Spanish word "vaca" (cow) returns a list of verses with "vaca" but also with "vacía" (empty). If the search is performed having set the interface language to English, the same search bring out the correct verses. The problem also shows up if the word "vacía" is searched which now brings out "vaca" in the results as well. Interestingly, if the word "vacía" is misspelled by leaving the letter "i" without the proper accent "í" then the search does not bring "vaca" as a result. Again all the confusing results appear when the application interface is set to Spanish. When the interface is set to English, the search comes out correctly even when searching for Spanish terms.