Metadata and exports

"Creative Cloud version 5.7.1"? I assume you mean Lightroom 5.7.1, yes? 

Have you checked through your process thoroughly, i.e. confirmed that the image you are exporting has keywords assigned, then confirmed that "All Metadata" is checked in the Metadata panel of the Export settings panel? Assuming you have done all that, and the output file still doesn't show the keywords when checked, the only other thing that I can think of is to go back to the original image in Lightroom and confirm that the specific keywords assigned to the image each have the "Include on Export" option enabled. You can do that very simply by using the Keywording panel and change the display (using the drop down list at the top) to select the "Will Export" display option, which as it's names suggests will display in the panel only those keywords that are set to be included on export. If the panel is empty, that would be the explanation for the "missing" keywords, and you would need to edit the individual keywords to change the export option accordingly.