Comment 18 for bug 1768010

Bootch (di-man) wrote 22 minutes ago: #17

>Steve Bian (freespace) wrote on 2018-05-03:
>>This issue is caused by MountFlags=slave in the systemd-udevd.service file. Historically 16.04 removed this flag to allow laptop-mode-tools to work:
>>
>>https://askubuntu.com/questions/1019865/why-does-ubuntu-16-04-remove-mountflags-slave-from-systemd-udevd-service
>>
>>In 18.04 this flag is preserved and as such when usbmount mounts filesystems they are mounted into systemd's private namespace and not visible to the user.
>>
>>A workaround is to override the MountFlag as described in:
>>
>>https://unix.stackexchange.com/a/441588/191141

>Did not helped me. There are no changes in system behavior.

It works after reboot.