Not sure, when this behaviour started, but haveged fails to load in the first
attempt for some time now. The service gets rescheduled then and in the second
attempt the start succeeds.
Does the first attempt happen too early?

haveged[250]: haveged: listening socket at 3
haveged[250]: haveged: restart in new root: /sysroot
systemd[1]: Starting Tell haveged about new root...
systemd[1]: haveged-switch-root.service: Succeeded.
systemd[1]: Started Tell haveged about new root.
haveged[250]: haveged: listening socket at 3
haveged[250]: haveged: Couldn't get poolsize
systemd[1]: haveged.service: Main process exited, code=exited, status=1/FAILURE
systemd[1]: haveged.service: Failed with result 'exit-code'.
systemd[1]: haveged.service: Service RestartSec=100ms expired, scheduling
restart.
systemd[1]: haveged.service: Scheduled restart job, restart counter is at 1.
haveged[744]: haveged: listening socket at 3

$ps | grep haveged
root       744     1  0 10:39 ?        00:00:00 /usr/sbin/haveged -w 1024 -v 0
-F