Same problem:
$ uname -a Linux 4.15.0-24-generic #26-Ubuntu SMP Wed Jun 13 08:44:47 UTC 2018 x86_64 x86_64 x86_64 GNU/Linux
$ systemd-analyze blame 5min 27.825s plymouth-quit-wait.service 3min 58.262s snapd.seeded.service 57.012s snapd.service 4.868s NetworkManager-wait-online.service
Same problem:
$ uname -a
Linux 4.15.0-24-generic #26-Ubuntu SMP Wed Jun 13 08:44:47 UTC 2018 x86_64 x86_64 x86_64 GNU/Linux
$ systemd-analyze blame quit-wait. service service wait-online. service
5min 27.825s plymouth-
3min 58.262s snapd.seeded.
57.012s snapd.service
4.868s NetworkManager-