FORTIGATE-AWS GWLB having issue with https ssl blocking with probe cert failed

Dear All, 

We want to implement FORTIGATE-AWS GWLB.

This is our reference.

https://aws.amazon.com/blogs/apn/centralized-traffic-inspection-with-gateway-load-balancer-on-aws/

https://fortinetweb.s3.amazonaws.com/docs.fortinet.com/v2/attachments/e129c4eb-867b-11eb-9995-00505692583a/FortiOS_7.0_AWS_Administration_Guide.pdf

But we having issue with https ssl blocking with probe cert failed both IN dan OUT https traffic to/from Internet.

The issue will happen when:

1. if policy using flow based mode, utm av+ips+ssl-inpsection, the traffic not block by ssl

2. if policy using proxy based mode, utm with av+ips+ssl-inpsection, the traffic block by ssl

3. if policy using proxy based mode, utm with  ssl-inspection only (no av, no ips), tthe traffic block by ssl

Already using cert-probe-failed ALLOW

According to this reference

https://community.fortinet.com/t5/FortiGate/Technical-Tip-How-to-allow-HTTPS-port-443-traffic-when/ta-p/200844

Now not blocking SSL, But..... the traffic IN and OUT , from / to INTERNET for https, is slow / not like normal behavior traffic if we test using curl from ec2 amazon Linux.

Did anyone having same issue?

How to resolve this?