Can't assign exported array of nodes

[Badaxis]

Godot version

v4.0.beta12.official [3c9bf4b], v4.0.beta13.official [caacade]

System information

Windows 10

Issue description

There seems to be an issue with typed array of nodes, assign in the inspector doesn't work.
For example I used:

@export var arr_node: Array[Node3D]

In the inspector I have the contextual menu to assign a node from the tree but when I select it, it's not assigned.

These work properly with the same contextual menu to assign:

@export var node: Node3D
@export var arr_path: Array[NodePath]

Steps to reproduce

1. Create a basic scene with a script
2. Export an Array[Node3D] or other node type
3. In the inspector, try to assign a node from the tree into the array

Minimal reproduction project

array_node.zip

[Gnumaru]

This also happens on beta 14. I haven't tested in earlier betas.

A nodepath array export is persisted differently than a node export or node array export, if I'm not mistaken. A nodepath value can be serialized and unserialized directly in the .tscn, but in the case of node exports I think there is some metadata juggling in order to make it work. I haven't looked the code but I think it should be something like serializing an array of nulls but, in the metadata, holding an array of nodepaths, and after unserializing, after the whole tree has been set up and every node exists in its expected path, then the metadata is used to get the nodes and fill the array.

[andersonmadeira]

Also saw this on beta 16.

[dark-elf1]

Still present on v4.0.beta.custom_build [d01ac9c] on linux.

[raulsntos]

Duplicate of #62916