The Shadow scheduler take over prematurely with the following messages in the event_demon logs:
CAUAJM_W_00144 The CA WAAE Shadow Scheduler appears to have failed over prematurely.
CAUAJM_W_40309 The CA WAAE Primary Scheduler is shutting down as the CA WAAE Shadow Scheduler has taken over.
Problem related to "HAPollInterval" parameter being set to 15 (default value) in file $AUTOUSER/config.$AUTOSERV.
The solution is to increase the value of "HAPollInterval" to 30 seconds in order to avoid the encountered issue.
Please make sure the Primary and Dual databases are in sync before restarting in full HADS mode.
Otherwise use "autobcp" in order to synchronize them if necessary.