When,

NAT between 1 inside interface to 2 outside interfaces.
Source address must be translated to related destination interface address is normally expected.

Example Configuration with endpoint-dependent mode

set interface ip address TenGigabitEthernet6/0/0           20.20.20.1/24
set interface ip address TenGigabitEthernet6/0/1.300    30.30.30.1/24
set interface ip address TenGigabitEthernet6/0/0.400    40.40.40.1/24
nat44 add address 30.30.30.1
nat44 add address 40.40.40.1
set int nat44 in TenGigabitEthernet6/0/0 out TenGigabitEthernet6/0/1.300
set int nat44 in TenGigabitEthernet6/0/0 out TenGigabitEthernet6/0/1.400

expected result:
packet from 20.20.20.1 to 30.30.30.2  expected translation is 30.30.30.1
packet from 20.20.20.1 to 40.40.40.2  expected translation is 40.40.40.1

But the chosen out NAT address seems to be always the last added one.