Logging in to WebZ from Firefox, allowing desktop notifications, and then logging out again, it becomes apparent that upon using the "Log Out" button from the interface, the Telegram Session remains active and must be terminated from another Telegram client. A side effect of this is that desktop notifications still appear even after logging out of WebZ, while the web-browser window remains open.
The session remains active. (This does not happen on WebK)
Firefox 88.0 (64-bit)