It may take a while for the default map rendering at https://www.openstreetmap.org/ to show up at all zoom levels. That is simply a matter of limited resources as it takes time to render all the map tiles and there are many edits occurring around the world all the time. If your changes show up in one zoom level they are in the database and will show up fairly soon at other zoom levels.
Regarding routing and navigation, OSM doesn’t actually do that itself. There are a number of companies and projects that use OSM data to provide routing and navigation apps and websites. Each of those companies and projects has their own schedule for when they update their internal databases to include the new edits in OSM. There are two choices for routing on https://www.openstreetmap.org/ OSRM and GraphHopper. Those are separate entities from OSM and while they update their databases fairly regularly they do not update in “real time” so there will be a delay, sometimes of weeks, before the routing will change.