Adding environment variables requires enabling unbound usage model

Following instructions at https://developers.cloudflare.com/workers/platform/environment-variables/#add-environment-variables-via-the-dashboard, I receive the error “Workers Unbound has not yet been enabled for this account. (Code: 10075)”.

If I try to enable Unbound usage model by going to Workers & Pages > Overview > “Both Workers & Pages now share the same default Usage Model setting. You current default Usage Model is Unbound. Change” > Unbound > Enable Usage Model > Agree I then get the error “A subscription is required to enable Workers Unbound”.

Account Plan Limits - https://developers.cloudflare.com/workers/platform/limits/#account-plan-limits

Environment Variables - https://developers.cloudflare.com/workers/platform/limits/#environment-variables

The two above links suggests free tier has 64 environment variables/worker. Is the documentation inaccurate, or am I doing something wrong?

This is related to a Cloudflare incident: https://www.cloudflarestatus.com/incidents/j71qjtgb4cgw. I was able to add the environment variables.