Finally, I was able to figure out the issue. Fundamentally, the issue was a bad/missing CSS file from a plugin. It was being masked by my deployment pipeline not updating the app_plugin files on the server. That meant that backoffice was looking for files that were not there and erroring out.
In short, everyone had the correct suggestions, but the deployment pipeline added a wrinkle that I hadn’t identified lol.
Thank you all for helping!