It seems to happen pretty much every time by now, but whenever I go to turn off/reboot my computer, it seems to always halt, generally after unmounting /var/home, with the systemd-journal-flush.service.
I've tried manually flushing before shutting down, to no avail, and the only fix related to it that I found online involved changing the flush configuration to have Storage=persistent, but I can't very well do that here to test it.
Same thing happens with ostree-finalize (earlier than journal-flush but always combined with it).
Even after a rebasing, be it with an update, kernel argument change, or even happened after I just updated grub with ujust, it halts for ups of 5 mins on shutdown until it eventually reaches the timeout and shuts it down.