HINT_$PHY$ is not working

Document ID : KB000106270
Last Modified Date : 13/07/2018
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I ran an SQL SELECT using hint key HINT_$PHY$ to do physical reads only but find that my index is still accessed. 
CA Datacom 15.1
Table involved in the SQL SELECT resides in an area for which a BA24 (blocksize alter) process has been run.
Once a BA24 process has been run, so even if that ended successfully , it is not possible to do physical sequential reading . 
After running DBUTLTY BACKUP/LOAD all physical reads will be restored.
Additional Information:
DEFECT DE370752 has been opened for the CBS Diagnostic report to reflect the use of physical data scan or not . And if not, for what reason.