There are some weird things going on in SQL*Plus with it, so you can see it's not Toad. The sample below is with uniqueid varchar2(5).
Copyright (c) 1982, 2016, Oracle. All rights reserved. Last Successful login time: Thu May 30 2019 07:27:02 -05:00 Connected to: Oracle Database 19c Enterprise Edition Release 188.8.131.52.0 - Production SQL> SELECT a.street.city.region.uniqueid FROM vw_address a; STREET.CIT ---------- HARRIS SQL> select deref(region) from vw_city; select deref(region) from vw_city * ERROR at line 1: ORA-22814: attribute or element value is larger than specified in type