I know this is a years-old thread, but there's no resolution mentioned, and I'm having the same problem. stop() is not destroying the data. I'm still logged in after calling it. I've tried stop(), I've tried destroy(), I've tried remove()... this data will not die. (I also can't overwrite it, once I've set a value.)
I also tried the
unset($_SESSION['some_name']) approach and still can't wipe out the data.
I'm using the default "out-of-the-box" session configuration, so FileHandler driver, etc. The user guide indicates this will "just work" reliably, but it's reliably just not working.
Either I'm doing something fundamentally wrong architecturally, or something in CI4 is broken (I'm currently on 4.3.3 but I don't think the changes in the one newer version would affect this). Since I can't even unset the value from $_SESSION my guess is that the problem (if it's not my error) is in the FileHandler driver. I'm now going to try switching to the DatabaseHandler driver to see if I can make some progress.
(BTW, after years of sticking with CI3, this is my first CI4 project, and there's a lot to learn. My Web development skills are also rusty and outdated in general. So, I fully recognize that this "bug" may instead be an error on my part.)
