401 error - OpenId configuration

Hello,

I continuously receive 401 error at the front-end at todolist call.
I checked the log at the back-end:

Unable to retrieve document from: 'https://TENANTNAME.onmicrosoft.com/TENANTID/v2.0/.well-known/openid-configuration'..
Microsoft.IdentityModel.LoggingExtensions.IdentityLoggerAdapter: Error: Message: IDX40001: Issuer: 'https://login.microsoftonline.com/81e60945-86db-4111-a558-324338a26215/v2.0', does not match any of the valid issuers provided for this application. , InnerException: IDX20803: Unable to obtain configuration from: 'https://TENANTNAME.onmicrosoft.com/TENANTID/v2.0/.well-known/openid-configuration'. Will retry at '0001. 01. 01. 0:00:00 +00:00'. Exception: 'System.IO.IOException: IDX20804: Unable to retrieve document from: 'https://TENANTNAME.onmicrosoft.com/TENANTID/v2.0/.well-known/openid-configuration'.
---> System.Net.Http.HttpRequestException: The requested name is valid, but no data of the requested type was found. (ernstyounghu.onmicrosoft.com:443)

I tried to switch between various nuget packages and instead of ciamlogin I use https://login.microsoft.com/TENANTID in the front end and https://TENANTNAME.onmicrosoft.com/ at the back-end.

Any idea?

Thanks,

Regards,

Adam