Instance stuck at 'Stopping' when installing on Centos7 AMI

[atoy3731]

Trying to get this working with a Centos 7 Base AMI. I've created the following systemd file and hibagent successfully starts:

[Unit]
Description=AWS Hibernate Service
After=network.target

[Service]
Type=forking
Restart=always
RestartSec=1
User=root
ExecStart=/usr/bin/hibagent -c /etc/hibagent-config.cfg

[Install]
WantedBy=multi-user.target

And the logs in /var/log/messages seem to be okay:

Aug 11 13:43:05 ip-10-2-1-225 hibagent: Will check if swap is at least: 7819 megabytes
Aug 11 13:43:05 ip-10-2-1-225 hibagent: Will check if swap is at least: 7819 megabytes
Aug 11 13:43:05 ip-10-2-1-225 hibagent: Info current pm_freeze_timeout (40 seconds) is greater than or equal to the requested (40 seconds) timeout, doing nothing
Aug 11 13:43:05 ip-10-2-1-225 hibagent: No swap is present, will create and initialize it
Aug 11 13:43:05 ip-10-2-1-225 hibagent: There's enough space (90321072128 present, 8210321408 needed) on the swap device: /
Aug 11 13:43:05 ip-10-2-1-225 hibagent: Info current pm_freeze_timeout (40 seconds) is greater than or equal to the requested (40 seconds) timeout, doing nothing
Aug 11 13:43:05 ip-10-2-1-225 hibagent: No swap is present, will create and initialize it
Aug 11 13:43:05 ip-10-2-1-225 hibagent: There's enough space (90321072128 present, 8210321408 needed) on the swap device: /
Aug 11 13:43:05 ip-10-2-1-225 hibagent: Initial checks are finished, daemonizing and writing PID into /run/hibagent
Aug 11 13:43:05 ip-10-2-1-225 hibagent: Initial checks are finished, daemonizing and writing PID into /run/hibagent
Aug 11 13:43:05 ip-10-2-1-225 hibagent: Locking all the code in memory
Aug 11 13:43:08 ip-10-2-1-225 hibagent: Starting the hibernation polling loop
Aug 11 13:43:08 ip-10-2-1-225 hibagent: Swap file size (8199864320 bytes) is already large enough
Aug 11 13:43:08 ip-10-2-1-225 hibagent: Running: /sbin/mkswap /swap
Aug 11 13:43:09 ip-10-2-1-225 hibagent: Running: /sbin/swapon /swap
Aug 11 13:43:10 ip-10-2-1-225 hibagent: Updating the kernel offset for the swapfile: /swap
Aug 11 13:43:10 ip-10-2-1-225 hibagent: Updating GRUB to use the device /dev/xvda1 with offset 318544 for resume
Aug 11 13:43:10 ip-10-2-1-225 hibagent: GRUB configuration is updated
Aug 11 13:43:10 ip-10-2-1-225 hibagent: Setting swap device to 51713 with offset 318544
Aug 11 13:43:10 ip-10-2-1-225 hibagent: Done updating the swap offset
Aug 11 13:43:10 ip-10-2-1-225 hibagent: Background swap initialization thread is complete.

However, when I initiate a HIbernate call from the AWS UI, it gets into a 'Stopping' state and stays there. I do get booted from the instance, and the only way to get back in is a hard stop and start.

Here's the logs right after I pushed the Hibernate button:

Aug 11 14:07:29 ip-10-2-1-225 systemd-logind: Suspend key pressed.
Aug 11 14:07:30 ip-10-2-1-225 NetworkManager[1261]: <info>  [1565532450.0699] manager: sleep: sleep requested (sleeping: no  enabled: yes)
Aug 11 14:07:30 ip-10-2-1-225 journal: Screen lock is locked down, not locking
Aug 11 14:07:30 ip-10-2-1-225 NetworkManager[1261]: <info>  [1565532450.0706] manager: NetworkManager state is now ASLEEP
Aug 11 14:07:30 ip-10-2-1-225 NetworkManager[1261]: <info>  [1565532450.0708] device (ens3): state change: activated -> deactivating (reason 'sleeping', sys-iface-state: 'managed')
Aug 11 14:07:30 ip-10-2-1-225 NetworkManager[1261]: <info>  [1565532450.0860] device (ens3): state change: deactivating -> disconnected (reason 'sleeping', sys-iface-state: 'managed')
Aug 11 14:07:30 ip-10-2-1-225 dbus[963]: [system] Activating via systemd: service name='org.freedesktop.nm_dispatcher' unit='dbus-org.freedesktop.nm-dispatcher.service'
Aug 11 14:07:30 ip-10-2-1-225 avahi-daemon[983]: Withdrawing address record for fe80::c18:78ff:fed4:4776 on ens3.
Aug 11 14:07:30 ip-10-2-1-225 systemd: Starting Network Manager Script Dispatcher Service...
Aug 11 14:07:30 ip-10-2-1-225 NetworkManager[1261]: <info>  [1565532450.1230] dhcp4 (ens3): canceled DHCP transaction, DHCP client pid 1396
Aug 11 14:07:30 ip-10-2-1-225 NetworkManager[1261]: <info>  [1565532450.1232] dhcp4 (ens3): state changed bound -> done
Aug 11 14:07:30 ip-10-2-1-225 avahi-daemon[983]: Withdrawing address record for 10.2.1.225 on ens3.
Aug 11 14:07:30 ip-10-2-1-225 avahi-daemon[983]: Leaving mDNS multicast group on interface ens3.IPv4 with address 10.2.1.225.
Aug 11 14:07:30 ip-10-2-1-225 dbus[963]: [system] Successfully activated service 'org.freedesktop.nm_dispatcher'
Aug 11 14:07:30 ip-10-2-1-225 nm-dispatcher: req:1 'connectivity-change': new request (5 scripts)
Aug 11 14:07:30 ip-10-2-1-225 nm-dispatcher: req:1 'connectivity-change': start running ordered scripts...
Aug 11 14:07:30 ip-10-2-1-225 avahi-daemon[983]: Interface ens3.IPv4 no longer relevant for mDNS.
Aug 11 14:07:30 ip-10-2-1-225 systemd: Started Network Manager Script Dispatcher Service.
Aug 11 14:07:30 ip-10-2-1-225 kernel: ixgbevf 0000:00:03.0: NIC Link is Up 10 Gbps
Aug 11 14:07:30 ip-10-2-1-225 NetworkManager[1261]: <info>  [1565532450.2005] device (ens3): state change: disconnected -> unmanaged (reason 'sleeping', sys-iface-state: 'managed')
Aug 11 14:07:30 ip-10-2-1-225 dnsmasq[1762]: no servers found in /etc/resolv.conf, will retry
Aug 11 14:07:30 ip-10-2-1-225 nm-dispatcher: req:2 'down' [ens3]: new request (5 scripts)
Aug 11 14:07:30 ip-10-2-1-225 chronyd[969]: Source 148.167.132.200 offline
Aug 11 14:07:30 ip-10-2-1-225 systemd: Reached target Sleep.
Aug 11 14:07:30 ip-10-2-1-225 chronyd[969]: Source 208.113.157.157 offline
Aug 11 14:07:30 ip-10-2-1-225 systemd: Starting Suspend...
Aug 11 14:07:30 ip-10-2-1-225 chronyd[969]: Source 74.6.168.72 offline
Aug 11 14:07:30 ip-10-2-1-225 chronyd[969]: Source 107.155.79.108 offline
Aug 11 14:07:30 ip-10-2-1-225 chronyd[969]: Can't synchronise: no selectable sources
Aug 11 14:07:30 ip-10-2-1-225 nm-dispatcher: req:2 'down' [ens3]: start running ordered scripts...
Aug 11 14:07:30 ip-10-2-1-225 systemd-sleep: Suspending system...

I also see the /swap file that is generated is around 8gb (the amount of RAM I have).

Is this just not compatible with CentOS? Or am I missing something? I've waited a half hour after hibernating and still no dice.