Changing shaders on Mac OS using Metal does not immediately apply in fullscreen mode

Description

Changing shaders (on the Snes9x-current core) using RetroArch_Metal on Mac OS 12.6.2 Monterey using the Metal driver does not immediately apply in fullscreen mode. For example, when using the scalefx-aa-fast preset, and then turning of shaders completely via Quick Menu => Shaders => Video Shaders = off, the previous shader stays in effect when resuming the emulation. It is necessary to exit fullscreen to make the shader changes take effect.

I already used a nightly build where the previous Metal bug with the slow down bug was fixed. My build is from January 7th.

Expected behavior

Shaders changes should take effect immediately when Apply changes is activated or when they are turned off completely.

Actual behavior

Shader changes only take effect when switching from fullscreen to windowed mode.

Version/Commit

• RetroArch: Metal Nightly Mac OS build from January 7th 2023

Environment information

• OS: Mac OS 12.6.2 Monterey

Start by reproducing the issue with RetroArch_Metal on macOS 12.6.2 in fullscreen mode, using the scalefx-aa-fast preset and the Quick Menu shader controls. Trace the Metal fullscreen shader-application path and verify that changing or disabling shaders takes effect without switching to windowed mode.