Laravel auth session suddenly not persisting

After doing some work strictly in the front end, not touching any controllers at all, suddenly my user session is not persisting between page redirects. I can register/login fine and it redirects to the home page without issue, but as soon as I go to another page, I'm logged out again.

Since I just used php artisan make:auth I have no idea how this system actually works, and thus no recourse to start debugging it. Can anyone help me out?

I also wonder if this has anything to do with the recent security crackdown on .dev and .test domains in modern browsers. Are they just not saving the cookies?

Thanks!