Not able to call beanstalk app via https from another beanstalk application

Question

I have 2 applications deployed in AWS Beanstalk. First application is an api gateway application thats calling the second application. I am able to call both the applications using http. The 2 applications are spring rest apps. If i call the first app (api gateway app) , it in turn calls the second app and I am getting the desired output. Now I changed the protocol for second app inside bean stalk from http to https. Went to the configuration -> Load balancer and added listener as per the image below. Now when i directly access the second app using https protocol, its working. But when I tried to access via the api gateway(first app) , its not working. Please note, inside api gateway app i changed the url of 2nd app from http to https.

Looks to be an issue of security groups. But not sure as I am able to access the 2nd app directly from my browser via https but the same is not responding when i call via the first app(api gateway).

Even I allowed all traffic for the 3 security groups each for the 1st app, 2nd app and the load balancer. But still its not working.

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Answer 1

3 Checks before any further answer:

1. Is your base url pointed correctly? (Assuming its importance as you are using api gateway)
2. Are there any external WAF rules? or Cloudflare?
3. Have you modified previous http rule to HTTPS and for that you have managed redirection and related settings, also check if you created a new rule in security groups or you just edited the default one?