I run into this often enough that it's becoming annoying. Open a new search panel, and start typing a word (such as judg and then various suggestions appear in the dropdown list. Now press the down arrow-key to select one of the suggestions ("judgement", say) and then press Enter. The selected suggestion's text should be added to the search text-box, but instead a search is started immediately (with the incomplete search text - "judg" in this case).
The same behaviour (failing to correctly handle Enter when selecting "suggestions" from drop-down menus appears throughout Logos. Very annoying, but perhaps a single code fix will fix the behaviour across the entire Logos.