PostGIS doesn't automatically convert WKB to GeoJSON

Yes, in 3.0 we added a cast from geometry to json, and that cast uses geojson as the output json encoding. If you want to still get hex you'll have to wrap up your geometry into a bytea in whatever query you are using to generate your row.

WITH r AS (
   SELECT ST_AsBinary(geom) AS geom, name, address
   FROM mytable
)
SELECT row_to_json(r.*) FROM r