Forgets session after 5 minutes (homestead related)

I'm having an issue with sessions. If I go to the login form of my app and login immediately, everything works perfectly. But if I go to the login page, let the page rest for 5 minutes or so, and then try to login, it doesn't work anymore.

I guess it's an issue with the sessions flash data. Because if I enter the wrong password in the form, I don't see error messages. The error messages do show if I submit the form without waiting for 5 minutes.

Here's some more info about my environment:

• session driver: file
• i'm using subdomains for different users (user.app.com)
• config/session.domain => null
• using homestead

Thanks.

EDIT:
Looks like the problem is homestead/vagrant related, don't have the issue with MAMP.