osmpgsql fails to load all data from OSM file

I have a project where I need to use osm2pgsql to load an OpenStreetMap file (osm.pbf).
(Using a command like this:

osm2pgsql -c -d database_name -U user -H localhost -W -S "path to style file" "path to osm-file")

The command runs with no errors, but whenever I use it for larger areas, data on relations are not imported (the table for relations is created in Postgres, but it is empty). Same thing for the road table. It works fine for smaller areas.

Any ideas as to what the issue might be and, how I can fix it?