There are a number of cases where queries in both pgadmin4 and pgadmin3 are done against pg_depend but falis to constrain the query on classid.
In particular, if for example a constraint and a sequence exists with the same oid (which is perfectly valid, as they are in different tables), a column will suddenly refer sequences that are completely incorrect. When we look up sequences, we have to make sure we only match dependencies against pg_class.
