This turns out to be a developer error and assumption.
I program with the OWNER user for connection to the database, so the drop-down list of Sequences shows the SequenceName as a non-owner-qualified version.
When changing the development connection to a program-user ( NOT the database owner...
Delphi XE 10.1 Berlin
DOA v4.4.1.0
Oracle 21c
accessing a Pluggable Database
Component: TOracelDataset
Property: SequenceField
Using the older version for Oracle 11, the SequenceField can be set for a sequence named GEN_VALUE from the drop-down list in the wizard.
The previous version...