After login with SDDM to X11 Plasma, I get a black screen with a cursor. Startx works on TTY2

I have a pretty fresh install of Manjaro. When logging in with SDDM after boot, I get a black screen with a cursor. I can switch to TTY2 and login and run startx, and I get to the plasma desktop just fine. It seems to have started after changing themes to kvantum-relax, but even resetting SDDM to default settings using the default config file, I am still unable to get to the desktop from SDDM.

Journalctl on sddm does not show ANY issues getting the session started. From other peoples issues on this it was typically a problem with startx (~/.xinitrc), but startx works fine for me. Is there anything else I can find that might help explain this?

Feb 28 14:09:04 twistedpaper sddm[10771]: Greeter session started successfully
Feb 28 14:09:04 twistedpaper sddm[10771]: Message received from greeter: Connect
Feb 28 14:09:09 twistedpaper sddm[10771]: Message received from greeter: Login
Feb 28 14:09:09 twistedpaper sddm[10771]: Reading from "/usr/share/xsessions/plasma.desktop"
Feb 28 14:09:09 twistedpaper sddm[10771]: Reading from "/usr/share/xsessions/plasma.desktop"
Feb 28 14:09:09 twistedpaper sddm[10771]: Session "/usr/share/xsessions/plasma.desktop" selected, command: "/usr/bin/startplasma-x11"
Feb 28 14:09:09 twistedpaper sddm-helper[10827]: [PAM] Starting...
Feb 28 14:09:09 twistedpaper sddm-helper[10827]: [PAM] Authenticating...
Feb 28 14:09:09 twistedpaper sddm-helper[10827]: pam_systemd_home(sddm:auth): systemd-homed is not available: Unit dbus-org.freedesktop.home1.service not found.
Feb 28 14:09:09 twistedpaper sddm-helper[10827]: [PAM] Preparing to converse...
Feb 28 14:09:09 twistedpaper sddm-helper[10827]: [PAM] Conversation with 1 messages
Feb 28 14:09:09 twistedpaper sddm-helper[10827]: gkr-pam: unable to locate daemon control file
Feb 28 14:09:09 twistedpaper sddm-helper[10827]: gkr-pam: stashed password to try later in open session
Feb 28 14:09:09 twistedpaper sddm-helper[10827]: [PAM] returning.
Feb 28 14:09:09 twistedpaper sddm-helper[10827]: pam_kwallet5(sddm:auth): pam_kwallet5: pam_sm_authenticate
Feb 28 14:09:09 twistedpaper sddm[10771]: Authenticated successfully
Feb 28 14:09:09 twistedpaper sddm-helper[10827]: pam_kwallet5(sddm:setcred): pam_kwallet5: pam_sm_setcred
Feb 28 14:09:09 twistedpaper sddm-helper[10827]: pam_unix(sddm:session): session opened for user tpaper(uid=1000) by (uid=0)
Feb 28 14:09:09 twistedpaper sddm-helper[10827]: pam_env(sddm:session): deprecated reading of user environment enabled
Feb 28 14:09:09 twistedpaper sddm-helper[10827]: gkr-pam: gnome-keyring-daemon started properly and unlocked keyring
Feb 28 14:09:09 twistedpaper sddm-helper[10827]: pam_kwallet5(sddm:session): pam_kwallet5: pam_sm_open_session
Feb 28 14:09:09 twistedpaper sddm[10771]: Auth: sddm-helper exited successfully
Feb 28 14:09:09 twistedpaper sddm[10771]: Greeter stopped.
Feb 28 14:09:09 twistedpaper sddm-helper[10827]: Starting: "/usr/share/sddm/scripts/Xsession \"/usr/bin/startplasma-x11\""
Feb 28 14:09:09 twistedpaper sddm[10771]: Session started

I have this problem on both 5.15.25-1 and 5.16.11-2 Manjaro Kernel versions. Both prior and after updating applications when switching.

 ██████████████████  ████████     tpaper@twistedpaper
 ██████████████████  ████████     OS: Manjaro 21.2.4 Qonos
 ██████████████████  ████████     Kernel: x86_64 Linux 5.16.11-2-MANJARO
 ██████████████████  ████████     Uptime: 40m
 ████████            ████████     Packages: 1173
 ████████  ████████  ████████     Shell: fish 3.3.1
 ████████  ████████  ████████     Resolution: 3440x1440
 ████████  ████████  ████████     DE: KDE 5.91.0 / Plasma 5.24.2
 ████████  ████████  ████████     WM: KWin
 ████████  ████████  ████████     GTK Theme: Breeze [GTK2/3]
 ████████  ████████  ████████     Icon Theme: Relax-Dark-Icons
 ████████  ████████  ████████     Disk: 1.4T / 3.2T (47%)
 ████████  ████████  ████████     CPU: AMD Ryzen 5 3600X 6-Core @ 12x 4.4GHz
 ████████  ████████  ████████     GPU: AMD Radeon RX 6900 XT (SIENNA_CICHLID, DRM 3.44.0, 5.16.11-2-MANJARO, LLVM 13.0.1)
                                  RAM: 4013MiB / 32066MiB