Header dependency between Shipping Method and Request Date does not work

We have added a Header dependency in oe_dependencies_extn package between Shipping Method and Request Date, but this not working and does not cause re-defaulting of the Request date when Shipping Method is changed.

x_extn_dep_tbl(l_index).source_attribute := OE_HEADER_UTIL.G_SHIPPING_METHOD;

x_extn_dep_tbl(l_index).dependent_attribute :=OE_HEADER_UTIL.G_REQUEST_DATE;

x_extn_dep_tbl(l_index).enabled_flag := 'Y’

l_index := l_index + 1;

Is this a bug or Oracle does not support this dependency ?

However the dependency added between the Shipping Method and Request Date on the Order Line is working.