password rejected on encrypted LVM after suspend

[fcolcord]

password rejected on encrypted LVM after suspend
Installation of 17.04 on fully encrypted USB

:~$ lsb_release -rd
Description: Ubuntu 17.04
Release: 17.04

Steps to reproduce.
Install 17.04 onto USB drive. Lenovo X250, 8GB RAM
Choose options for fully encrypted.
No additional packages installed.
No changes to settings.
(Wanted to test suspend behaviour, since it was such a disaster on previous ubuntu installation.)

choose suspend from top right icon.
Wait for suspend to finish
press power button
wait for login password request
enter same password
expected behaviour: log in
actual behaviour: password rejected
something like: "invalid password, please try again"

password accepted when screen goes blank, or on 'lock'

I've read through the following searches and don't see a similar bug report.

https://launchpad.net/ubuntu/+bugs?field.searchtext=password+encrypted+LVM&search=Search&field.status%3Alist=NEW&field.status%3Alist=INCOMPLETE_WITH_RESPONSE&field.status%3Alist=INCOMPLETE_WITHOUT_RESPONSE&field.status%3Alist=CONFIRMED&field.status%3Alist=TRIAGED&field.status%3Alist=INPROGRESS&field.status%3Alist=FIXCOMMITTED&field.assignee=&field.bug_reporter=&field.omit_dupes=on&field.has_patch=&field.has_no_package=

https://askubuntu.com/search?q=encrypted+usb+password+17.04

https://launchpad.net/ubuntu/+bugs?field.searchtext=password+17.04&search=Search&field.status%3Alist=NEW&field.status%3Alist=INCOMPLETE_WITH_RESPONSE&field.status%3Alist=INCOMPLETE_WITHOUT_RESPONSE&field.status%3Alist=CONFIRMED&field.status%3Alist=TRIAGED&field.status%3Alist=INPROGRESS&field.status%3Alist=FIXCOMMITTED&field.assignee=&field.bug_reporter=&field.omit_dupes=on&field.has_patch=&field.has_no_package=

ProblemType: Bug
DistroRelease: Ubuntu 17.04
Package: gnome-screensaver 3.6.1-7ubuntu5
ProcVersionSignature: Ubuntu 4.10.0-35.39-generic 4.10.17
Uname: Linux 4.10.0-35-generic x86_64
ApportVersion: 2.20.4-0ubuntu4.5
Architecture: amd64
CurrentDesktop: Unity:Unity7
Date: Sun Oct 8 12:20:10 2017
EcryptfsInUse: Yes
GnomeSessionIdleInhibited: No
GnomeSessionInhibitors: None
GsettingsGnomeSession:
 org.gnome.desktop.session session-name 'ubuntu'
 org.gnome.desktop.session idle-delay uint32 300
InstallationDate: Installed on 2017-10-01 (6 days ago)
InstallationMedia: Ubuntu 17.04 "Zesty Zapus" - Release amd64 (20170412)
SourcePackage: gnome-screensaver
Symptom: security
Title: Screen locking issue
UpgradeStatus: No upgrade log present (probably fresh install)