Unable to display 'https' Geo-Server layers in Ckan

I am using the following stack on ‘development’ server

• Instance 1 : Geoserver 2.18, Apache & Cent OS 7
• Instance 2 : Ckan & Cent OS 7
• SSL Configured : On instance 1

Problem statement : For regular Geo-server ‘http’ request in Ckan it works fine but for ‘https’ request it gives an error "Could not proxy resource because a connection error occurred-. [SSL: CERTIFICATE_VERIFY_FAILED]"

1. Verified certificates on Server it’s fine.
2. Both machines are able to connect properly.
3. Proxy and other part are configured okay.
4. Geo-server request is trying to go outside firewall (not sure why ?)
5. Researching more on my side.