ADB2C Login with Subdomain

[kapildeb]

We have configured a subdomain for a existing Tenant of ADB2C. this subdomain URL is working when it is opened directly in the browser. it is showing the login page and and working as expected. But when we are using nextjs to authenticate and using next-auth library first of all it is redirecting to the Tenant URL for login. Now in code we have override the issuer URL of Azureadb2c config in as in library code is written like:
**

const issuer =
options.issuer ??
https://${tenantId}.b2clogin.com/${tenantId}.onmicrosoft.com/${primaryUserFlow}/v2.0

**

we found that after providing the issuesr url in Azureadb2c config it is providing the Auth error
http://localhost:3000/auth/signin?callbackUrl=http%3A%2F%2Flocalhost%3A3000&error=OAuthSignin

and browser is in continuous in loop due the the OAuth error.