OpenGL: The last instance of MultiMesh incorrectly sets the color

[DmitriySalnikov]

Godot version

v4.0.beta14.official [28a2463]

System information

Windows 10, OpenGL

Issue description

Vulkan and Mobile:

OpenGL:

At first I thought it was related to set_buffer(), but it turned out that set_instance_* also work incorrectly.
Probably the custom information is also set incorrectly, but I haven't checked it yet.

Steps to reproduce

• Open MRP
• In the editor, select MeshInstance3D node and change the Count property
• -- or --
• Start the project and move the slider

You can also switch the renderer to Vulkan and compare.

Minimal reproduction project

set_buffer().zip

[DmitriySalnikov]

2D is affected too.
Vulkan and Mobile:

OpenGL:

Here is the updated MRP:
set_buffer().zip