The RunOnlyOnIP functionality works still fine.
But with ticket it was introduced that in a load balanced environment - if the RunOnlyOnIP is null, the scheduler is started just on one server (provided they are connected via hazelcast).
My test case involved the following:
started at the same time two servers linked by hazelcast
check in idempiereMonitor - everything working fine - schedulers just running on one server
restarted the server where the schedulers are not running
all the schedulers now are running twice
Probably the cause is that the schedulers are being started before the server joins the other hazelcast node.