Hello ,
In destination NAT pool , we can either add an IP address or address range . We cannot add noncontiguous IP address . It will override each other .
If you wanted to load balance between same IP on different ports ( 80 & 443 ) you can try creating 2 different NAT pool and creat 2 different rule . One for 80 and another for 443 .
eg :
set security nat destination pool test-1 address 192.168.1.2
set security nat destination pool test-2 address 192.168.1.3
set security nat destination rule-set test from zone untrust
set security nat destination rule-set test rule 1 match destination-address 1.2.3.4/32
set security nat destination rule-set test rule 1 match destination-port 80
set security nat destination rule-set test rule 1 then destination-nat pool test-1
set security nat destination rule-set test rule 2 match destination-address 1.2.3.4/32
set security nat destination rule-set test rule 2 match destination-port 443
set security nat destination rule-set test rule 2 then destination-nat pool test-2