FTP timing out

A little puzzled. The FTP connects with a newly built server but times-out before it can retrieve a list of the webroot files. It is odd because I would think applications like updating a WordPress site use FTP, though perhaps a built-in FTP? For the most part the accounts are WordPress sites that function in all regards.

If it was a network interface issue then I would think other issues would have surfaced but this is literally the only issue with a freshly built machine. I am at a loss as to how to debug. We can build a new server and move the handful of accounts placed on it - naturally, we would rather find out exactly what the issue is. The hardware is well tested in many of our latest servers and includes an Intel SSD boot drive. We have not had issues with the hardware as of yet so perhaps a corrupted FTP install? What would a more experienced Virtualmin server admin do now? Deleting a recreating the FTP account does nothing and because it seems to be the same with all accounts it is a server wide issue. You just get the first few folders and then it never can retrieve a list of the files.

I would love to hear a suggestion.