We have similar setup , 2x SG230 in Active/Passive HA After updating to 9.308-16 , RED10 goes up and down every 30 sec , and the remote site is completely unreachable we do not have the possibility to rollback to previous firmware [:(]
A VERY quick fix (I think), take a backup, reinstall the UTM from ISO and restore from backup file...If this issue is mission critical...then it's worth a try....nb. you will lose logs and eventual email quarantine...