I use cookie in my site for login management. I user logs in the cookie dies with the session, if user flags "Keep me logged in" when logging in a long time cookie persists. In the long time cookie I store a hashed informations (user_id,password_hash). It's used to check if user is still logged in in a new session and I use these informations to check if user can access site without relogin. I read in some article about GDPR that technical cookies are allowed without any disclaimer. I can consider my login cookie a technical cookie since I store only these informations? Do I need to show the disclaimer in this case?
So a cookie to keep a user logged in, requires consent. But the checkbox "Keep me logged in" is appropriate to gain consent. So in your case you do not need to display a cookie banner.