I’m running the following:
Amazon EC2 Instance
Ubuntu 18.04.4 Server LTS
Apache 2.4.29
PHP 7.2.24-0ubuntu0.18.04.3
Wordpress 5.4
Let’s Encrypt Certificates

I’m trying to activate a purchased plugin: Modula Gallery, when I click the activate button, I receive the following error:

stream_socket_client(): SSL operation failed with code 1. OpenSSL Error messages:error:14094410:SSL routines:ssl3_read_bytes:sslv3 alert handshake failurestream_socket_client(): Failed to enable cryptostream_socket_client(): unable to connect to ssl://wp-modula.com:443 (Unknown error)

I have reached out to the plugin’s tech support, but they haven’t seen this error before. Google isn’t yielding much either. Here is the output from running “sudo certbot certificates”

- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
Found the following certs:
  Certificate Name: MyDomain.org-0001
    Domains: MyDomain.org
    Expiry Date: 2020-07-04 19:07:27+00:00 (VALID: 88 days)
    Certificate Path: /etc/letsencrypt/live/MyDomain.org-0001/fullchain.pem
    Private Key Path: /etc/letsencrypt/live/MyDomain.org-0001/privkey.pem
  Certificate Name: MyDomain.org
    Domains: MyDomain.org www.MyDomain.org
    Expiry Date: 2020-07-04 18:52:34+00:00 (VALID: 88 days)
    Certificate Path: /etc/letsencrypt/live/MyDomain.org/fullchain.pem
    Private Key Path: /etc/letsencrypt/live/MyDomain.org/privkey.pem
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -

I have seen posts online that indicate the intermeditate certificate isn’t installed properly, but the output above indicates the fullchain.pem is present, and therefore contains it. Anyone have any ideas?

Thank you.