It looks a like failure to boot, with the last visible message on tty1 like this:
[ 4.902533] Bluetooth: hci0: Malformed MSFT vendor event: 0x02
This message also appears, in red color, near the end of dmesg output:
[ 4.809519] IPv6: ADDRCONF(NETDEV_CHANGE): wlan0: link becomes ready
[ 4.886689] Bluetooth: hci0: Waiting for firmware download to complete
[ 4.887421] Bluetooth: hci0: Firmware loaded in 1871281 usecs
[ 4.887582] Bluetooth: hci0: Waiting for device to boot
[ 4.902502] Bluetooth: hci0: Device booted in 14694 usecs
[ 4.902533] Bluetooth: hci0: Malformed MSFT vendor event: 0x02
[ 4.909349] Bluetooth: hci0: Found Intel DDC parameters: intel/ibt-19-0-4.ddc
[ 4.911481] Bluetooth: hci0: Applying Intel DDC parameters completed
[ 4.912493] Bluetooth: hci0: Firmware revision 0.4 build 15 week 45 2022
[ 4.978678] Bluetooth: MGMT ver 1.22
[ 15.018726] pci 0000:00:0d.0: deferred probe pending
[ 33.726082] systemd-journald[478]: Time jumped backwards, rotating.
But, the system is actually booted. The user can log in on tty2 and issue
startx && exit
and get the expected plasma desktop.
There are some forum reports on arch forum, but no solutions that I can find. The error seems to be mostly cosmetic.
I saw sddm got updated today -- I wonder whether that might be involved in this issue?