PDB$SEED differences between v$datafile and dba_data_file

Hello all,

I have several questions about PDB$SEED.

Our monitoring tool shows offline datafiles for the PDB$SEED for SYSTEM, SYSAUX and UNDO tablespace.

First question...is this the standard for the PDB$SEED?

When I query name and status of v$datafile the datafiles with status ONLINE are displayed. But if I query file_name and online_status of dba_data_files the status is shown with OFFLINE.

Why are different statuses displayed here?

If I stop the PDB$SEED with shutdown immediate and then start it again with startup, the online_status is displayed now as ONLINE in dba_data_files.