@samsls Thanks for following up with me on this!
I used the Directus CLI with a Token for the admin account to import the data into a "default vanilla installation of Directus". Everything imported without any issues. Afterwards, I deployed the front end using Vercel from a private GitHub repo.
Based on the reply from @girish, I put some additional configuration into the env.sh file and restarted Directus.
export CORS_ENABLED="true"
export CORS_ORIGIN="domain1.com,app-name.vercel.app"
export CORS_METHODS="GET,POST,PATCH,DELETE,OPTIONS"
export CORS_ALLOWED_HEADERS="Content-Type,Authorization"
export CORS_EXPOSED_HEADERS="Content-Range"
export CORS_CREDENTIALS="true"
export CORS_MAX_AGE="18000"
I've placed that into the env.sh as a wide-open test to at least see if I could get it working, but no luck.
I know there are some other options, that you can force some of these settings into your Vercel deployment using the vercel.json file, but haven't gotten to that yet.
There are some open issues that it seems they're looking into based on their GitHub.
CORS issues for client portal in "PROD" like deployment
Fetch the data from the server side instead of the client?