Could not read from remote repository

Hi all. First, I’ll get versions of things out of the way:
GitLab 8.7.3
GitLab Shell 2.7.2
GitLab API v3
Git 2.7.4
Ruby 2.1.8p440
Rails 4.2.6
PostgreSQL 9.2.15

Next, a diagram showing what we currently have configured to allow offsite users access to our GItlab environment:

We have our gitlab server behind a subnet that’s private (192.168…) with a webserver that proxies the connection which has a publicly accessible IP so git fetch and other cli things work properly. All of this was working as expected until we upgraded our webserver over the past weekend. It was on CentOS 5 and we upgraded to 6. When users attempt to git anything, they get the following error:

git fetch origin integration
ssh: connect to host port 2224: Connection timed out
fatal: Could not read from remote repository.

Please make sure you have the correct access rights
and the repository exists.

Please let me know if you’d like logs of things.