If I try to open up domains in the schema browser it runs this command
Select :own OWNER, o.object_id, o.OBJECT_NAME, o.STATUS, o.LAST_DDL_TIME, o.CREATED, d.cols,
replace(d.data_display, CHR(0), ' ') data_display,
replace(d.data_order, CHR(0), ' ') data_order,
replace(d.selector, CHR(0), ' ') selector,
decode(bitand(d.flags, 64), 64, 'Yes', 'No') as IsJSON,
decode(bitand(d.flags, 32), 32, 'Yes', 'No') as IsFlexible
from sys.user_objects o, sys.user_domains d
where o.object_type = 'DOMAIN'
and o.object_name = d.name;
but FLAGS is not a column in user_domains view (or all_domains or dba_domains)