We have a global multisites configuration with about 20 sites. We recently setup two new slave sites based on the same template. One is for Hungary and one for Poland.

We pointed the two separate domain for both sites to the managed server’s IP address.

We setup in multisites for the Hungary site to be within sites/hu folder and the Poland site to be within the sites/pl folder. We also setup the domains within multisites to match these respective folders.

The Hungary site properly pulls up the sites/hu files properly. Poland pulls up the sites/de files which is the Czech site.

Within all of these sites subfolders is a pointer to the master htaccess file. We can pull up the Poland site using the master domain/sites/pl/index.php. We can pull up test html or test php files within the sites/pl file using the proper domain. We just cannot pull up the Poland joomla site using the Poland domain. Hungary pulls up just fine and it is configured the exact same, but the Poland site keeps redirecting to a different slave site.

You seems to speak about domains that you have assigned to a specific directory (/pl or /hg)

First you need to verify the setup of your HTTP server (cPanel, plesk, ....) to verify that the domain point to the correct directory (document root).
You can use the "hello.php" file to test the setup of the apache.

You should normally get the correct path displayed with each domains.hg/hello.php domains.pl/hello.php

If you don't receive the correct answer, this is probably because you used a redirection in your server configuration that redirect to the "de".

Once you will be sure that you have correctly configured your server, you can return in JMS and verify the definition of the slave site.
You must have the domain declared with the correct deployment folder that correspond to what is displayed by the "hello.php".

See tutorial video 7 for the "hello worlds" application
www.jms2win.com/en/tutorial#jms12x-7

I've found the problem. Even though everything was definitely conigured correctly within the multisites admin, the multisites/config_multisites.php file was the source of the problem. The Poland domain name was pointing to the wrong site ID. Not sure how that could have possibly happened. Potentially a bug in multisites.

You mentioned a potential error in the "config_multisites" but didn't show what is wrong and what is good.

Without the "wrong value" and the "correct value"