Setting node process_mode to Disabled then back to Inherit doesn't reset the mode properly

[pouleyKetchoupp]

Godot version

3.3.2.stable, 4.0.dev (92f20fd)

System information

Windows 10

Issue description

When changing the process_mode property on a node that is at least 2 levels deep in the tree (both parents are set to Inherited), setting the mode back to Inherited doesn't reset the current state properly.

Example in the editor: the node stays grayed out even after setting it back to Inherited. Its state is reset properly only after setting the parent node to any mode then back to Inherited:

Steps to reproduce

Using the minimal reproduction project:

1. Open project in editor
2. Select Node3 in the scene tree
3. Set process_mode to Disabled
4. Observe the node is grayed out (correct)
5. Set process_mode back to Inherited
6. Observe the node is still grayed out (incorrect)

Minimal reproduction project

disable-node-bug-4.0.zip