I enabled error reporting and, while I saw many errors with various permutations of “Strict Standards: Declaration” in them, this one stood out as a likely culprit:
Parse error: syntax error, unexpected ‘<‘ in /var/www/vhosts/icln.cbox.twohatsconsulting.com/wp-content/themes/cbox-theme/dashboard/templates/cpanel_header.php on line 2
I looked in that file and noticed an extra <?php opening tag, so I deleted it as a test and the page seems to work now! Sweet.
I’m not a Github user, so I’m not sure how to best submit that as a needed change, but it’s clearly an error that should be corrected. Let me know if there’s some way I can contribute there, and thanks again for the help.