Search through the list of unfiltered rooms rather than the rooms in the state which are already filtered by the search text

src/components/views/rooms/RoomSublist.tsx

@@ -420,7 +420,7 @@ export default class RoomSublist extends React.Component<IProps, IState> {
             room = this.state.rooms && this.state.rooms[0];
         } else {
             // find the first room with a count of the same colour as the badge count
-            room = this.state.rooms.find((r: Room) => {
+            room = RoomListStore.instance.unfilteredLists[this.props.tagId].find((r: Room) => {
                 const notifState = this.notificationState.getForRoom(r);
                 return notifState.count > 0 && notifState.color === this.notificationState.color;
             });