Blockbench: v4.10.4
CPM Plugin: v0.6.17_pre1

The issue:
When a Null Object is present in the scene (Null Objects are used for IK rigging), and the Animate mode is active, Blockbench starts exhibiting abnormal behavior. This only occurs when creating a CPM Model in Blockbench, and does not occur with Blockbench's standard model types.

Video demonstration:
https://www.youtube.com/watch?v=zWWHKAC3OLQ

To reproduce:

• Create a new CPM model.
• While in Edit mode, add a Null Object. (Top menu: Edit > Add Null Object)
• Switch to Animate mode.
• Add a new animation, and then select it.
• In the Outliner, select any object (Null Object or Group) and attempt to move the object.

At this point, Blockbench should be in this exact state:

• A Null Object present in the Outliner, in Animate mode, with an animation selected, and any object selected.

Result:

• All objects will transform with continuous acceleration.
• Animation playback can be started, but cannot be stopped. If there are any keyframes in the timeline, they will not play correctly. User must navigate to either Edit or Paint mode to stop animation playback.
• Undo will not restore previous states correctly, and undo history is now in a dirty state.

Additionally, while in the Animation tab with a Null Object in the scene:

• Navigate the top menu: File > Preferences > Settings...
• Attempt to close the Settings window.
• This window will refuse to close, either via the Close button or the [X] button.

Issues only appear to occur while in the Animate mode. No issues appear to be present while in the Edit or Paint tabs.