Nginx Load balancer troubleshooting and fix

Job ID: 31093037

Budget: $10 – $30 USD

Hi I have 2 VPS which is load-balanced via NGINX LB
2 VPS has the same file.
When I visit each VPS separately all is okay
But when I visit from the load balancer IP all website loads without 4 specific files those showing 502 bad gateway error

Need urgent help if you can work now on Anydesk. Cause it's local VM

Only knock if you are confident about the issue. I'm in trouble!!
Related categories: PHP System Admin Linux Apache Nginx