Despite converting my number field to a text field (thanks for the tip Geonet), my Page Query is still not working in Pro. I have it in a secondary copy of the layer driving the Map Series. However when it is set, all the features disappear. I'm needing this in both the main map frame, as well as a small inset map, to cut out the "noise" of irrelevant features. Any ideas why this may not be working please?