Freeciv causes suspend to fail

After installing and playing Freeciv (gtk2) on an old computer the suspend stopped working. Rebooting fixed the problem.

It didn't happen immediately, I could play several times but after a day or three suspend would stop working. And would work for awhile after rebooting.

I checked my notes and only installing Freeciv and Ubuntu updates were done during this time.

I rebooted again and haven't played Freeciv since and have not had any more suspend problems.

I installed Freeciv (gtk2) on a new computer running Ubuntu 18.04 and didn't see the problem right away. Turned out that the less I played Freeciv the longer it took the problem to surface. After more than a week suspend stopped working on this computer.

Rebooted and ran Freeciv, leaving it up all the time and the suspend problem happened the second day.

Rebooted and haven't run Freeciv and no suspend problems for nearly two weeks.

What I expected to happen
 Ubuntu suspend works no matter how many hours I spend playing Freeciv
What happened
 Ubuntu suspend fails to work some time after playing Freeciv
Steps to repeat
 Install Freeciv (gtk2) under Ubuntu 18.04
 Play Freeciv off and on for a few days suspending the computer when not needed
 At some point the suspend will fail

Description: Ubuntu 18.04.4 LTS
Release: 18.04
Freeciv (gtk2) 2.5.10-1 (from software center)

ProblemType: Bug
DistroRelease: Ubuntu 18.04
Package: freeciv-client-gtk 2.5.10-1
ProcVersionSignature: Ubuntu 5.3.0-42.34~18.04.1-generic 5.3.18
Uname: Linux 5.3.0-42-generic x86_64
ApportVersion: 2.20.9-0ubuntu7.12
Architecture: amd64
CurrentDesktop: ubuntu:GNOME
Date: Wed Mar 18 10:04:51 2020
InstallationDate: Installed on 2019-12-15 (93 days ago)
InstallationMedia: Ubuntu 18.04.3 LTS "Bionic Beaver" - Release amd64 (20190805)
ProcEnviron:
 PATH=(custom, no user)
 XDG_RUNTIME_DIR=<set>
 LANG=en_US.UTF-8
 SHELL=/bin/bash
SourcePackage: freeciv
UpgradeStatus: No upgrade log present (probably fresh install)