Works on Localhost, not live: "Error: net::ERR_CONTENT_LENGTH_MISMATCH 200 (OK)"

I can run my program as localhost but when I try to run it through AWS it fails to connect.

I am very much a rookie at AWS but my developer took a look and couldn't figure it out. Not sure what to think about that but regardless I am stuck and wondered if anyone else has seen this issue.

He did say the issue was likely caused by me turning the server off, then restarting a few days later which we didn't know updates your AWS IP addresses.

We are running 2 ec2 instances and one RDS server.

There are 6 Python APIs: Short string is returned well; long string is not returned.

Any assistance is appreciated.