I find your message pretty baffling. osmand is an app that uses osm
data. So pretty such everyone here uses it. It has support for
downloading maps for different areas. It works. It routes correctly
between points when the route crosses a border between download files.
E.g. if you have both Massachusetts and New Hampshire, and route from
Boston to Manchester, that works fine.
OSM data is sometimes better than other maps, sometimes worse, and it
depends on which sub-part you care about. Generally
trails/parks/etc.are much better in OSM, and POI completeness is worse
in areas with a low nerd density.
If you're going to suggest something is wrong, please actually try it
and report something factual, or post a link to some statement about
osmand if you want to ask question. Saying that you heard a rumor that
there is something wrong, and putting problem in quotes (which means
that you don't really mean problem, but something else) doesn't seem
likely to lead to helpful answers.
So:
install osmand and see if it works; read the docs. If you have an
actual problem ask for help, but be precise about what you did
go to
www.openstreetmap.org and ask for routes. Note that this is a
site about the data osmand uses, and not osmand.