Hi Spencer,
Copy the file _meta.php
from your parent X or PRO theme, from this directory \framework\views\global
Paste that file to your Child theme in the same directory, create the folder if needed.
Edit the _meta.php
file that is on your child theme, in that file you’ll see:
<meta charset="<?php bloginfo( 'charset' ); ?>">
<meta name="viewport" content="width=device-width, initial-scale=1.0">
Paste your custom meta code between those lines.
That is not an issue with the Theme nor the site, please instruct your client to Turn Off the Compatibility Mode of IE
https://www.nfc.usda.gov/Publications/HR_Payroll/Reporting/Bulletins/2015/REPT-15-04att.htm
Hope it helps,
Cheers!