Xubuntu 18.04 sometimes logs out when lid is closed

[slumbergod]

I have Xubuntu set only to turn off the screen when the lid is closed.
Despite this, sometimes, I open the laptop lid to find a log-in screen. xfce4-power-manager has decided to ignore my settings and suspended the system. I have to log in again and all my applications have been terminated meaning I cannot leave processes running reliably if I close the lid.

ProblemType: Bug
DistroRelease: Ubuntu 18.04
Package: xfce4-power-manager 1.6.1-0ubuntu1
ProcVersionSignature: Ubuntu 4.15.0-22.24-generic 4.15.17
Uname: Linux 4.15.0-22-generic x86_64
ApportVersion: 2.20.9-0ubuntu7.1
Architecture: amd64
CurrentDesktop: XFCE
Date: Sat Jun 2 21:11:15 2018
InstallationDate: Installed on 2018-04-27 (37 days ago)
InstallationMedia: Xubuntu 18.04 LTS "Bionic Beaver" - Release amd64 (20180426)
SourcePackage: xfce4-power-manager
UpgradeStatus: No upgrade log present (probably fresh install)

[Theo Linkspfeifer (lastonestanding)]

Please attach ~/.xession-errors.old (error log of the previous session) to this bug report after encountering this bug again.

[Launchpad Janitor (janitor)]

[Expired for xfce4-power-manager (Ubuntu) because there has been no activity for 60 days.]

[Darko Veberic (darko-veberic-kit)]

this resurfaced in ubuntu 18.10.

although i have suspend off everywhere (only switch off display), i got, i assume, a logout to a lock screen where my power-manager settings are ignored and the laptop goes into suspend (from which it wakes up only with a reboot, but this is another story).

in the Settings | Power Manager | Security tab i set the "automatically lock" to "never", but the lock occurs anyway and checking these settings again after logging-in, they turn out to be set back to "when the screen saver is activated".