a bug I just came along: use two clone modifiers on one object and disable the upper one. Save your scene and load it again. Now both modifiers are enabled.
I am not sure this is related but right now I am working on a scene with some clone modifiers. The scene is crashing a lot (like 10 times a day). I am using Max 2020.2 which is pretty stable on all other scenes. So I assume it might be caused by clone modifier.
I am using the current Clone Plugin version, Max 2020.2, Win10