Safe Graphics Mode after updates [KDE neon]

I installed ~300 updates via Discover a couple of nights ago. I sensed something had gone amiss when Firefox both crashed and wouldn't resume after I opened a brand new session (ie. no tab reloads). I got the crash report box, then a subsequent crash.

Full reboot. Up comes the login screen. The password field cursor is unresponsive to keyboard input, and isn't blinking. The virtual keyboard button isn't responsive either, despite my having mouse movement. I then reboot, this time via recovery mode, which loads the crappy fallback graphics driver with only 1024*768 resolution available. This persists after package repair attempts and sudo apt autoremove to clear disk space. My AMDGPU drivers don't seem to be functional at all.

var/log/apt/term.log (below) reveals the latest driver versions are 24.x. Presumably these were upgraded during the update, prior to which I was on an earlier working version? That's all I can think of.

What other logs should I consult for troubleshooting? Would driver reversions work? How do I get back to a normal display? Your input is appreciated!

Preparing to unpack .../libglapi-mesa_24.0.0~rc3+git2401302259.6dadb9b032c~j~mesarc4_amd64.deb ...
Unpacking libglapi-mesa:amd64 (24.0.0~rc3+git2401302259.6dadb9b032c~j~mesarc4) over (23.3.3+git2401121944.151cd31e051~j~mesarc4) ...
Setting up libglapi-mesa:amd64 (24.0.0~rc3+git2401302259.6dadb9b032c~j~mesarc4) ...
Preparing to unpack .../libgbm-dev_24.0.0~rc3+git2401302259.6dadb9b032c~j~mesarc4_amd64.deb ...
Unpacking libgbm-dev:amd64 (24.0.0~rc3+git2401302259.6dadb9b032c~j~mesarc4) over (23.3.3+git2401121944.151cd31e051~j~mesarc4) ...
Preparing to unpack .../libgbm1_24.0.0~rc3+git2401302259.6dadb9b032c~j~mesarc4_amd64.deb ...
Unpacking libgbm1:amd64 (24.0.0~rc3+git2401302259.6dadb9b032c~j~mesarc4) over (23.3.3+git2401121944.151cd31e051~j~mesarc4) ...
Setting up libgbm1:amd64 (24.0.0~rc3+git2401302259.6dadb9b032c~j~mesarc4) ...
Preparing to unpack .../libegl-mesa0_24.0.0~rc3+git2401302259.6dadb9b032c~j~mesarc4_amd64.deb ...
Unpacking libegl-mesa0:amd64 (24.0.0~rc3+git2401302259.6dadb9b032c~j~mesarc4) over (23.3.3+git2401121944.151cd31e051~j~mesarc4) ...
Setting up libegl-mesa0:amd64 (24.0.0~rc3+git2401302259.6dadb9b032c~j~mesarc4) ...
Preparing to unpack .../libgl1-mesa-dri_24.0.0~rc3+git2401302259.6dadb9b032c~j~mesarc4_amd64.deb ...
Unpacking libgl1-mesa-dri:amd64 (24.0.0~rc3+git2401302259.6dadb9b032c~j~mesarc4) over (23.3.3+git2401121944.151cd31e051~j~mesarc4) ...
Setting up libgl1-mesa-dri:amd64 (24.0.0~rc3+git2401302259.6dadb9b032c~j~mesarc4) ...
Preparing to unpack .../libglx-mesa0_24.0.0~rc3+git2401302259.6dadb9b032c~j~mesarc4_amd64.deb ...
Unpacking libglx-mesa0:amd64 (24.0.0~rc3+git2401302259.6dadb9b032c~j~mesarc4) over (23.3.3+git2401121944.151cd31e051~j~mesarc4) ...
Setting up libglx-mesa0:amd64 (24.0.0~rc3+git2401302259.6dadb9b032c~j~mesarc4) ...
Preparing to unpack .../025-libegl1-mesa-dev_24.0.0~rc3+git2401302259.6dadb9b032c~j~mesarc4_amd64.deb ...
Unpacking libegl1-mesa-dev:amd64 (24.0.0~rc3+git2401302259.6dadb9b032c~j~mesarc4) over (23.3.3+git2401121944.151cd31e051~j~mesarc4) ...
Preparing to unpack .../048-libosmesa6_24.0.0~rc3+git2401302259.6dadb9b032c~j~mesarc4_amd64.deb ...
Unpacking libosmesa6:amd64 (24.0.0~rc3+git2401302259.6dadb9b032c~j~mesarc4) over (23.3.3+git2401121944.151cd31e051~j~mesarc4) ...
Preparing to unpack .../060-libxatracker2_24.0.0~rc3+git2401302259.6dadb9b032c~j~mesarc4_amd64.deb ...
Unpacking libxatracker2:amd64 (24.0.0~rc3+git2401302259.6dadb9b032c~j~mesarc4) over (23.3.3+git2401121944.151cd31e051~j~mesarc4) ...
Preparing to unpack .../080-mesa-va-drivers_24.0.0~rc3+git2401302259.6dadb9b032c~j~mesarc4_amd64.deb ...
Unpacking mesa-va-drivers:amd64 (24.0.0~rc3+git2401302259.6dadb9b032c~j~mesarc4) over (23.3.3+git2401121944.151cd31e051~j~mesarc4) ...
Preparing to unpack .../081-mesa-vdpau-drivers_24.0.0~rc3+git2401302259.6dadb9b032c~j~mesarc4_amd64.deb ...
Unpacking mesa-vdpau-drivers:amd64 (24.0.0~rc3+git2401302259.6dadb9b032c~j~mesarc4) over (23.3.3+git2401121944.151cd31e051~j~mesarc4) ...
Preparing to unpack .../082-mesa-vulkan-drivers_24.0.0~rc3+git2401302259.6dadb9b032c~j~mesarc4_amd64.deb ...
Unpacking mesa-vulkan-drivers:amd64 (24.0.0~rc3+git2401302259.6dadb9b032c~j~mesarc4) over (23.3.3+git2401121944.151cd31e051~j~mesarc4) ...
Preparing to unpack .../102-xserver-xorg-video-amdgpu_23.0.0+git2401241940.4d7a9a6~j~mesarc0_amd64.deb ...
Unpacking xserver-xorg-video-amdgpu (23.0.0+git2401241940.4d7a9a6~j~mesarc0) over (23.0.0+git2309251950.31a092a~j~mesarc0) ...
Setting up mesa-vulkan-drivers:amd64 (24.0.0~rc3+git2401302259.6dadb9b032c~j~mesarc4) ...
Setting up mesa-vdpau-drivers:amd64 (24.0.0~rc3+git2401302259.6dadb9b032c~j~mesarc4) ...
Setting up xserver-xorg-video-amdgpu (23.0.0+git2401241940.4d7a9a6~j~mesarc0) ...
Setting up libgbm-dev:amd64 (24.0.0~rc3+git2401302259.6dadb9b032c~j~mesarc4) ...
Setting up libxatracker2:amd64 (24.0.0~rc3+git2401302259.6dadb9b032c~j~mesarc4) ...
Setting up mesa-va-drivers:amd64 (24.0.0~rc3+git2401302259.6dadb9b032c~j~mesarc4) ...
Setting up libosmesa6:amd64 (24.0.0~rc3+git2401302259.6dadb9b032c~j~mesarc4) ...
Setting up libegl1-mesa-dev:amd64 (24.0.0~rc3+git2401302259.6dadb9b032c~j~mesarc4) ...

Further info

• KDE neon 5.27, dual boot
• Kernel 6.5.0
• X11
• GPU R9 390, single monitor setup