Https website - in s3 -- call node api running on ec2

I have a website running in an s3 bucket Traffic is routed using route 53 I have created a certificate with ACM I have added the certificate to cloudwatch etc

My site is now https when i try calling my api which is node/express, and exists task run by service on ec2 instance

I have a ALB load balancer set up, with listeners pointing to target groups that point to my api.

Has always worked fine until I added https.

I have tried running my api with 2 ports exposed- 8086 and 8443 ---- using another certificate created in ACM (this may be wrong)

But i dont think traffic is even making it that far. I get a mix of errors related to the certificates invalid, or common name being off, depending on what I do.

There is a https listener with a default certificate etc, but I still think Im missing something major here, or a more elegant way to allow my webpage to talk to my api.