Apache reverse proxy to node.js app using HTTPS not working correctly


I currently have a number of web apps running on different subdomains of my website and have managed to set up HTTPS no problem using Let’s Encrypt and Certbot. I also have a Node app running on my server (http://localhost:3001) that all my web apps connect to. I’ve set up a subdomain for my Node.js app to run on and aquired an SSL certificate for it.

In the VirtualHost entry for this subdomain, I’m using ProxyPass to point to my Node app and my configuration looks like this:

<VirtualHost MY_IP_ADDRESS:443>
ServerName server.myserver.com
ProxyPass / http://MY_IP_ADDRESS:3001/
ProxyPassReverse / http://MY_IP_ADDRESS:3001/
SSLCertificateFile /etc/letsencrypt/live/server.myserver.com/cert.pem
SSLCertificateKeyFile /etc/letsencrypt/live/server.myserver.com/privkey.pem
Include /etc/letsencrypt/options-ssl-apache.conf
SSLCertificateChainFile /etc/letsencrypt/live/server.myserver.com/chain.pem

The problem I’m facing is that when I try and access https://server.myserver.com the browser informs me the connection is not secure (and as a result, this is now true of any of my other apps that access server.myserver.com).

When it comes to server configuration, my knowledge is very limited so I’m at a loss as to what the problem is. Is it an Apache issue or does my Node app need to use HTTPS (my research so far suggests not…)?