Viewport's Control derived nodes bug when in-editor

[nonunknown]

Godot version:
3.2.2 RC1

OS/device including version:
Ubuntu 20.04

Issue description:
I'm making a plugin using viewports in-editor (tool keyword) and UI doesnt work, I'm using as basis the demo 3d-in-2d.

It works when you press F6 to run game, but in-editor doesnt work.

Steps to reproduce:

• Download MRP below
• Install inside addons/ of an existing project
• Open Node.tscn
• Press F6
• See the button working
• Now activate the plugin
• press F8 to open the dialog
• See that button is not working

Minimal reproduction project:
file.zip

[KoBeWi]

The minimal project needs to be updated for Godot 4.4 or newer.

[AThousandShips]

Closing due to lack of response, if you provide the requested information this can be reopened