I had similar problem, turned out something was corrupted in MicroB settings. I renamed the .mozilla folder in /home/user to something else and after a reboot the browserd daemon recreated it and the cookies were working (and since I only renamed it, I copied some of the old settings back after that).
Well, not exactly - the browser there is not Gecko based, but WebKit. And the passwords not remembered is not an issue - its just not supported currently by the browser.