Microsoft user unable to sign in

Hi,

we are using Azure AD authentication and one new user cannot sing in (user not created yet but we have autocreate enabled). User is present in DomainUsers table, I have completed Reset Cache ...
In datasource logs I can find a message:

NullReferenceException - Object reference not set to an instance of an object. at Devolutions.Server.Managers.AuthenticationProvider.SkipAuthentication(LoginContext loginContext) at Devolutions.Server.Managers.AuthenticationProvider.AuthenticateUser(LoginContext loginData, String userName, String password) at Devolutions.Server.Managers.AuthenticationProvider.ValidateUser(LoginContext loginData, String userName, String password, LoginAttemptEntity loginAttempt) at Devolutions.Server.Controllers.APIControllers.V2.BackendApiController.DoLogin(ISessionContext context, ParsedLoginParameter loginParameter, LoginContext& loginData)

I think this is the first user to be created since we upgraded from 2020.3.18. Anyhow in test environment (which is already on 2022.3.6) it worked (most of users are disabled there). Is it DVLS limitation, I see it says 50 users license (we have 858 users)...
DVLS: 2022.3.4

Best regards,
Rok