For some reason, the drop-down select for the certificate is not showing when I go to add it to the HTTPS listener for my EC2 instance. In the ACM, it is "Issued", so I don't see why it shouldn't show up.
HTTPS Listener
Here's the ACM console, shows my certificate is issued
Based on the comments.
The reason for not being able to use imported SSL cert into ACM on ALB, is because its too long. The import cert is RSA 4096-bit, however, ALB (and other AWS services) are compatible with 2048-bit RSA (RSA_2048) or 1024-bit RSA (RSA_1024) as explained in:
The certificate imported into ACM is using an algorithm other that 1024-bit RSA or 2048-bit RSA.
The possible solution is to use IAM for these certificates:
ACM supports RSA certificates with a 4096 key length and EC certificates. However, you cannot install these certificates on your load balancer through integration with ACM. You must upload these certificates to IAM in order to use them with your load balancer.
