I am having the same or similar issue with PDF-Xchange v 9.4, build 363.0. For example, suppose my pdf has the following lines on a page:
LINE 1:...word1
LINE 2:word2...
Here are the two kinds of searches I do:
Search 1: Proximity: "Words from the Same Page", Search Field: ["word1 word2"]
Search 2: Proximity: "Only Adjacent Words", Search Field: [word1 word2]
Search 1 returns no results, but Search 2 returns one result.
IMO, both kinds of searches should manifest the same behavior, ie find the two word phrase even though the its words are split across lines. I use Search-1-style searches all the time because I only want the search results to list one page per hit even if the phrase appears multiple times on a single page.
Note that I've looked into the Contents tab and examined how the words are broken up into text objects and this behavior seems to have nothing to do with how the words are broken up into text objects.
I've attached a sample document. Try Search 1 and Search 2 with word1=human and word2=nature. Search 1 returns 2 results, and Search 2 returns 3 results.