Troubleshoot and Fix Connectivity Issues at Ubuntu Nginx Server with Linode Load Balancers

I have an ubuntu nginx apache server on a Linode cloud. It was recently configured to work with Linode’s load balancers using their api to update required certbot certificates. Since these changes have been made, the server has been experiencing various connectivity issues, from 500 errors initially to constant time out errors now. I am looking for someone who is great at troubleshooting and fixing connectivity issues related to ports, ssl, and load balancing. The previous programmer who set this configuration up is unresponsive, so please have excellent communication skills and professional integrity. The site had no connectivity issues until these recent changes and the load balancing was setup in preparation for higher traffic loads.

This job would be done with a remote desktop and should be quick if you have experience with similar configurations and issues.