How to auto signout b2b webapp from azure ad authentication v2 openid connect implemetented in .net framework in 15 mins

I have being working in web app with single sign-on ad authentication v2 with OpenID connect in .NET framework. Every time when I try to Sign-out, ‘Which account do you want to sign out of?’ page is coming to select account even if one account is logged in. It prevents from auto sign-out in 15 mins. I have tried with ‘ExpireTimeSpan’ in CookieAuthenticationOptions, startup.auth.cs and its relogging without password. I have also tried with deleting cookies, session and providing login_hint in singout but it didn’t logged out completely.

I have also tried to set Conditional Access in azure portal, but its minimum time out is 1hrs and its not based on inactivity.

Please provide me mechanisms to signout completely in 15 mins using azure ad openid authentication V2 version in .net frame work so that users need to provide password after 15 mins of inactivity.signout accounts