Your login is based on a cookie, which means that each browser on each device you use requires a login. Once you log in, that cookie is set and unless you log out or clear it, that browser on that device will stay logged in. I think it expires eventually, but not at the rate you describe. If you experience anything different, please provide the specifics of the device and browser (names and versions) and we will look into it. That includes any browser plug ins that may effect cookies like ad blockers and so on. Thanks for your report.