As far as I know it is only listed in the addons.cfg file if you add it there.
Stuff that is installed via the UI is normally listed in the jsondb directory.
You did not add it to the addons folder ( which depends on the OS/environment ) /usr/share/openhab/addons ?
Since the add-on-UID starts with jar I would say that the add-on is installed in the addons-folder. It can’t be removed from UI because UI can’t delete that file.