95-dm-notify.rules in dmsetup is only shipped in bionic and up. So I suspect that xenial, does not have udev synchronisation in dmsetup package.
xenial: https://packages.ubuntu.com/search?suite=xenial&arch=any&searchon=contents&keywords=95-dm-notify.rules
bionic: https://packages.ubuntu.com/search?suite=bionic&arch=any&searchon=contents&keywords=95-dm-notify.rules
95-dm-notify.rules in dmsetup is only shipped in bionic and up. So I suspect that xenial, does not have udev synchronisation in dmsetup package.
xenial: https:/ /packages. ubuntu. com/search? suite=xenial& arch=any& searchon= contents& keywords= 95-dm-notify. rules
bionic: https:/ /packages. ubuntu. com/search? suite=bionic& arch=any& searchon= contents& keywords= 95-dm-notify. rules