I find the Gizmo search is completely messed up if initiated after selecting a general view tab such as "Recently Added" or "Recently Played" (assuming you have defined such views or similar). If you first select a "simple" tab such as "Artist" or "Year (release)", then go back to Search, Gizmo may do better. I find it also has a tendency to shuffle tracks in the search result playlist, or play something that was not selected. All of this is easily confirmed by looking under Playing Now on the server itself for the renderer targeted by Gizmo.
Other Android players apps for MC do far more reliable searches. MO 4Media is very clean, with results being nicely grouped by type. JRemote2 does OK, but results are not as clearly grouped by type. The BubbleUPnP Android player does OK, dividing results into albums and tracks. On the other hand, JRiver Panel struggles, providing long lists of tracks which I find pretty useless.