On fast WAN links (>5MBit) it’s recommended to enable inter-site change notification. This feature is enables inter-site replications behave the same way as intra-site replication does (replication < 15min).
ADSI Edit > CN=Configuration… > CN=Sites > CN=Inter-Site Transport > CN=IP > open “Properties” of a siteLink
Change value to 1
Repadmin /syncall /force /APed