Isn’t it a duplicate of this one?
https://www.openstreetmap.org/node/634187532

Just in case: the OsmAnd~ app uses an offline map, so you have to download an update every now and then, otherwise you map want to add objects that are already on the map.
You can activate the "Live updates" to get a fresh copy.

To update, you can do: Menu > Download maps > Updates > Live updates > Belgium > Update now