Fullscreen not working on Wayland

[nfp0]

Description

When running RetroArch in Wayland mode, and having it set to fullscreen, it opens in fullscreen, as expected. But when I go and run a game on a core, it reverts back to a small window.

This does not happen when forcibly running RetroArch on X11 mode, where fullscreen works as expected. From the cores I tested, it happens on Mesen, bsnes-mercury and Mupen64Plus-Next. It does NOT happen on Genesis Plus GX, mGBA and SameBoy.

I've tried Vulkan, GL and GLCore but they all have the same behavior. The Windowed Fullscreen Mode setting makes no difference.

Pressing F makes the window resize to a different sized window, and pressing F a second time makes it finally go fullscreen.

Expected behavior

RetroArch should respect the fullscreen option.

Actual behavior

RetroArch returns to a small window when starting a game.

Steps to reproduce the bug

1. Open RetroArch on Wayland.
2. Enable Start in fullscreen mode and save your settings.
3. Start a game on Mesen, bsnes-mercury or Mupen64Plus-Next.
4. Observe RetroArch going back to windowed mode.

Bisect Results

I know it was happening at least as far back as 1.10.2, but probably before that too.

Version/Commit

• RetroArch: 1.11.1

Environment information

• OS: Manjaro KDE