Try to use 127.0.0.1 Instead of localhost

Browsers treat localhost differently than regular domains, but 127.0.0.1 behaves more like a standard domain.

Update your hosts file to map admin.localhost to 127.0.0.1:

127.0.0.1   localhost
127.0.0.1   admin.localhost

Access your application via http://127.0.0.1/login and http://admin.127.0.0.1/dashboard.