found my issue. Documentation could use a little clarity. While it states the API URL should be:
This has subsequently had the ‘/v1/authorize’ removed. In productive deployments, this will likely resemble:
https://{company}.okta.com/oauth2/{authServerId}/
“default” is the API authServerID that comes with Okta. Usually oidc clients have no issues using it. So when configuring galaxy oidc_config.xml and oidc_backend_config.xml, instead of https://{company}.okta.com/oauth2/{authServerId}/ use https://${company}.okta.com/oauth2/