Comment # 10 on bug 1165946 from Franck Bui

Then your issue boils down to figure out why the swap is deactivated in your
case.

Can you try to reboot with debug logs enabled (append "printk.devkmsg=on debug"
to the kernel command line), make sure that the swap is inactive and attach the
output of "journalctl -b -o short-monotonic" ?

Thanks.