--- a/src/MacSrc/OpenGL.cc
+++ b/src/MacSrc/OpenGL.cc
@@ -455,10 +455,30 @@
 #ifndef __ANDROID__
     // See opengl_resize()'s comment above.
     SDL_GL_MakeCurrent(window, context);
-#endif
 
     // Done rendering to the frame buffer, reset back to normal
     BindFrameBuffer(nullptr);
+#else
+    // BindFrameBuffer(nullptr) (glBindFramebuffer/glBindRenderbuffer to id
+    // 0) means "the real window surface" - on desktop that's SDL's actual
+    // GL window, but this app's real presentation target is never that
+    // SDLSurface's own EGL surface at all - it's the OpenXR swapchain's
+    // per-image FBOs, set up separately in xr_swapchain.c. Whatever
+    // framebuffer/renderbuffer 0 actually resolves to for gl4es in this
+    // configuration, binding it here reliably left gl4es reporting a
+    // persistent GL_INVALID_OPERATION (1282) - confirmed by bisecting
+    // through this whole render path with per-call checkpoints, all clean
+    // right up until "after opengl_end_frame", the one immediately after
+    // this exact call.
+    //
+    // The bind is also functionally dead on Android regardless of that:
+    // by the time anything next draws, Shock.c's SDLDraw() has already
+    // run xr_frame_begin() -> xr_swapchain_acquire(), which rebinds to
+    // that frame's real swapchain FBO before opengl_swap_and_restore()
+    // (the only thing that draws before the next opengl_start_frame()'s
+    // own BindFrameBuffer(&backupBuffer)) runs - so skipping it changes
+    // nothing about what actually gets rendered where.
+#endif
     palette_dirty = false;
 }