Add reference to issue

src/renderers/webgl/WebGLTextures.js

@@ -1133,7 +1133,7 @@ function WebGLTextures( _gl, extensions, state, properties, capabilities, utils,
 
 				_gl.blitFramebuffer( 0, 0, width, height, 0, 0, width, height, mask, _gl.NEAREST );
 
-				_gl.bindFramebuffer( _gl.FRAMEBUFFER, renderTargetProperties.__webglMultisampledFramebuffer );
+				_gl.bindFramebuffer( _gl.FRAMEBUFFER, renderTargetProperties.__webglMultisampledFramebuffer ); // see #18905
 
 			} else {