unable to select "sd-wan" as Outgoing Interface in ipv6 policy

Found the cause, kernel to old.

May I know the solution to your problem? I have the same problem..

Hello @Charlez79 and @hoisn ,
I have confirmed this is working with 6.0.14, 6.0.18, 7.2.8 and 7.4.4. Could be just a glitch on your end.
Galileo-kvm52 # get sys status
Version: FortiGate-VM64-KVM v6.0.14,build0457,211118 (GA)
Virus-DB: 1.00000(2018-04-09 18:07)
Extended DB: 1.00000(2018-04-09 18:07)
Extreme DB: 1.00000(2018-04-09 18:07)
IPS-DB: 6.00741(2015-12-01 02:30)
IPS-ETDB: 0.00000(2001-01-01 00:00)
APP-DB: 6.00741(2015-12-01 02:30)
INDUSTRIAL-DB: 6.00741(2015-12-01 02:30)
Serial-Number:
IPS Malicious URL Database: 5.00139(2024-08-11 07:30)
Botnet DB: 4.00888(2024-08-01 22:01)
License Status: Valid
VM Resources:
BIOS version: 04000002
Log hard disk: Available
Hostname: Galileo-kvm52
Operation Mode: NAT
Current virtual domain: root
Max number of virtual domains: 10
Virtual domains status: 1 in NAT mode, 0 in TP mode
Virtual domain configuration: disable
FIPS-CC mode: disable
Current HA mode: standalone
Branch point: 0457
Release Version Information: GA
FortiOS x86-64: Yes
System time: Sun Aug 11 17:15:26 2024

Galileo-kvm52 # conf firewall policy6

Galileo-kvm52 (policy6) # sh
config firewall policy6
edit 1
set name "Test"
set uuid 1d39aa38-5814-51ef-84ae-1e0c615d017b
set srcintf "port1"
set dstintf "virtual-wan-link"
set srcaddr "all"
set dstaddr "all"
set action accept
set schedule "always"
set service "ALL"
set nat enable
next
end

Regards,
Rishab