VMAX3 recoverable snapshots Oracle 12.1 fuzzy datafile

Hi,

We are testing recoverable snapshots.

We take snapshot of sg which contains ASM DATA and REDO diskgroups plus we take a backup of controlfile to filesystem.

We do not use 'begin backup / end backup'  as we are on Oracle 12.1 and we can use the 'snapshot time' feature.

ASM DATA contains datafiles only

ASM REDO contains redolog, controlfile

We then restore the DATA sg child only which replace the ASM DATA diskgroup. The REDO diskgroup is not replaced.

We try to recovery the database using the command below:

recover database until cancel using backup controlfile snapshot time '2019-08-30 11:13:02';

Though the database alert.log complains the datafile are in fuzzy status like the snapshot was not consistent.

Question: is there any setup needed on the Oracle side for using the 'snapshot time' feature in the recovery command ?

Thank you

Ma