SCUMM: MOONBASE: Main menu screen goes black in default (OpenGL) render mode

[Mardeg]

Architecture: arm64 (Raspberry Pi 400)
OS: Debian GNU/Linux 11 (Bullseye)
Kernel: Linux 6.1.21-v8+

Moonbase Commander version: 1.0/Windows/English (All data files copied to rPi after installing from CD)
SCUMMVM version: 2.9.0git (July 11 2024) Snap

Expected behaviour: Main menu remains visible

Actual behaviour: After intro completes without problems, a "partially visible" main menu appears for a few seconds then goes black. Moving the mouse around and clicking where buttons would normally be visible still works. If doing so before it goes black on any buttons except single/multiplayer mode, those screens appear normal until returning to Main menu, upon which the same behaviour occurs. Clicking either single or multiplayer buttons results in the screen immediately going and remaining black while audio still plays and it still responds to mouse clicks.
The described behaviour happens regardless of Full Screen being selected or V-sync being unselected in SCUMMVM settings for the game.

Workaround: Switching the Render Mode in ScummVM settings for the game to "SDL surface" prevents the screen going black, and graphics remain visible/game is playable when clicking single/multiplayer. This mode resizes the SCUMMVM window down to the original resolution of the game, I'm guessing.

Screenshot: Partially visible main menu before it goes black

[AndywinXp]

I can't reproduce it on Windows, maybe someone can on Linux?

[eriktorbjorn]

I can't reproduce it in Linux, with OpenGL mode. I didn't use any shader, though. (Just pointing that out since the screenshot looked a bit scanline-y.)

[Mardeg]

Replying to eriktorbjorn:

I can't reproduce it in Linux, with OpenGL mode. I didn't use any shader, though. (Just pointing that out since the screenshot looked a bit scanline-y.)

There are definitely no shaders used, the other screens don't have that effect so I'm not sure why just the Main Menu briefly looks like that before going black. If it helps I should mention I've also not seen this bug on any other of the games I've run so far on the rPi in ScummVM. Are there any similar games to Moonbase Commander I should try on this machine to see if they also do this?

Here are the specs of the Raspberry Pi 400 if anyone is looking to reproduce the environment:

SoC: 1.8Ghz Broadcom BCM2711 quad-core Cortex-A72 (ARMv8-A) 64-bit
GPU: Broadcom VideoCore VI
Supports a resolution of up to 4K and OpenGL ES 3.0 Graphics
RAM: 4GB LPDDR4 SDRAM

[AndywinXp]

Just to offer some context: the scanlines are actually part of a particular scanline fading effect which is done on the menus.

[Mardeg]

I just upgraded my OS from Bullseye to

OS: Debian GNU/Linux 12 (Bookworm)
Linux 6.6.31+rpt-rpi-v8

I am now no longer able to reproduce this bug.

The only weird thing of note is that the game runs fine even in ScummVM version 2.8.1 (Snap)