Godot crashes when using `cast_to` on a node that precedes GDNative node in tree

First of all, sorry for no stack trace: this is reproducible only with `release` builds for some reason...

Here's my code:
```cpp
// goapplanner.cpp
void GOAPPlanner::initialize(Array actions) {
Godot::print(Object::cast_to(actions[0])->get("name").operator String());
}
```

Here's the tree:
```
- parent
- agent
- empty_node (empty node of type Node with nothing inside)
- goapplanner (with GDNS running previous code)
```

Within `agent`, I have the following code:
```gdscript
func _ready():
$goapplanner.initialize([$empty_node])
```
The above code succeeds and prints `empty_node`. However, when I unload the scene to load another (by using `parent.queue_free()`), the game segfaults.

If I move `empty_node` AFTER `goapplanner`, the crash does not happen.

This is strange since I don't even keep the reference to `Node*` anywhere, I just cast `actions[0]` to `Node*` and then throw it away. Do `cast_to`-ed objects have to be marked/freed somehow?

Any ideas about what's going on here?