Exported PackedArrays are consistently reset in open scenes on script reload

[imp0s5ible]

Tested versions

v4.3.stable.official [77dcf97]

System information

Godot v4.3.stable - Windows 10.0.22621 - Vulkan (Forward+) - dedicated AMD Radeon RX 5700 XT (Advanced Micro Devices, Inc.; 31.0.24031.5001) - AMD Ryzen 9 3950X 16-Core Processor (32 Threads)

Issue description

If you save/touch a script that exports a PackedArray (I have tested Float32/64, Int32/64 and Color), then when reloading the script the editor silently resets the array to the default value given in the script in any scene that's opened.

I have tested and this does not occur with regular Array[float] or other Arrays.

If the undo history has modifications to the exported array, you can go back to that and then back to the present to restore it.

Minimum reproduction script:

class_name ArrayTester extends Node

@export var arr : PackedFloat64Array = [1, 2, 3]

Steps to reproduce

1. Create an empty project
2. Insert a node in the scene
3. Attach the above script to the node
4. Touch or save the script file to cause a reload (no need to make any actual modifications)
5. Focus the editor window

Minimal reproduction project (MRP)

Reproducible in an empty project