Hi @lautaroramos and welcome to the Auth0 Community! 
It sounds like you’ve got bot detection on a customized Classic Universal Login page. The users in this case are going back to the login page either with the back button or they have bookmarked the login prompt with an old state parameter. This is a legacy behavior that is still supported in Classic Universal Login.
One way to solve this issue and allow the user to keep going to that URL with an invalid state is to configure the tenant’s Login URL in the settings:
This is a URL in the application, that triggers the authorization flow. ie. it redirects to /authorize with the correct parameters to start the authorization flow.
I believe this should solve the problem and is transparent to the end-user.
Please read more about this scenario here:
Let me know if this helps!
Best Regards,
Colin