I had a look at journalctl. I am not very adept at it or understanding what it says, but I
found some curious things just before it hangs:
Sep 23 21:13:19
node-1w7jr9y9ftt7b9r339kpge4hj.ipv6.telus.net systemd[1]: Started
user(a)988.service - User Manager for UID 988.
Sep 23 21:13:19
node-1w7jr9y9ftt7b9r339kpge4hj.ipv6.telus.net audit[1]: SERVICE_START
pid=1 uid=0 auid=4294967295 ses=4294967295 subj=system_u:system_r:init_t:s0 >
Sep 23 21:13:19
node-1w7jr9y9ftt7b9r339kpge4hj.ipv6.telus.net systemd[1]: Started
session-c1.scope - Session c1 of User sddm.
Sep 23 21:13:19
node-1w7jr9y9ftt7b9r339kpge4hj.ipv6.telus.net audit[1281]: USER_START
pid=1281 uid=0 auid=4294967295 ses=4294967295 subj=system_u:system_r:xdm_t:s>
Sep 23 21:13:19
node-1w7jr9y9ftt7b9r339kpge4hj.ipv6.telus.net sddm-helper[1281]: Starting
X11 session: "" "/usr/bin/sddm-greeter --socket /tmp/sddm-:0-jEzEIX
--th>
Sep 23 21:13:19
node-1w7jr9y9ftt7b9r339kpge4hj.ipv6.telus.net sddm-greeter[1297]: could
not connect to display :0
Sep 23 21:13:19
node-1w7jr9y9ftt7b9r339kpge4hj.ipv6.telus.net audit[1297]: ANOM_ABEND
auid=4294967295 uid=988 gid=986 ses=4294967295 subj=system_u:system_r:xdm_t:>
Sep 23 21:13:19
node-1w7jr9y9ftt7b9r339kpge4hj.ipv6.telus.net sddm-greeter[1297]: Could
not load the Qt platform plugin "xcb" in "" even though it was found.
Sep 23 21:13:19
node-1w7jr9y9ftt7b9r339kpge4hj.ipv6.telus.net sddm-greeter[1297]: This
application failed to start because no Qt platform plugin could be initiali>
Available platform plugins are: eglfs, linuxfb, minimal, minimalegl, offscreen, >
Sep 23 21:13:19
node-1w7jr9y9ftt7b9r339kpge4hj.ipv6.telus.net systemd[1]: Created slice
system-systemd\x2dcoredump.slice - Slice /system/systemd-coredump.
Sep 23 21:13:19
node-1w7jr9y9ftt7b9r339kpge4hj.ipv6.telus.net audit: BPF prog-id=79
op=LOAD
Sep 23 21:13:19
node-1w7jr9y9ftt7b9r339kpge4hj.ipv6.telus.net audit: BPF prog-id=80
op=LOAD
Sep 23 21:13:19
node-1w7jr9y9ftt7b9r339kpge4hj.ipv6.telus.net audit: BPF prog-id=81
op=LOAD
Sep 23 21:13:19
node-1w7jr9y9ftt7b9r339kpge4hj.ipv6.telus.net systemd[1]: Started
systemd-coredump(a)0-1298-0.service - Process Core Dump (PID 1298/UID 0).
I am not sure what to make of it, but it appears that when the ethernet is used, sddm
wants to start plasma in X11 mode?
As I mentioned, when I have the ethernet cable pulled out and the wifi on only, then it
works. I haven't tried leaving ethernet plugged in but having wifi set to off (and
manually start it once logged in only when required).