Install.js not respecting local npm repo

My organisation uses Nexus for serving npm packages. And my local npm registry is configured to use the same. Running npm get registry returns the Nexus registry url.

But when I do npm install for this repo, during the postinstall step of electron it runs the script node install.js which is connecting to github.com instead of the Nexus registry.

I am getting below error RequestError: connect TOMEOUT 140.82.121.3:443

Do I need any other configuration for this?