### Godot version

master ([06ccbfe](https://github.com/godotengine/godot/commit/06ccbfe8eec6e840db3df2360dc2804386f940b8))

### System information

PopOS 22.04

### Issue description

Sometimes the doc page is broken when the engine is closed and then restarted.
Closing the doc and opening it again fixes it.

![2023-05-27_22-15](https://github.com/godotengine/godot/assets/3624853/ed202a55-03e8-420a-bc1c-ccfc7f7cd02a)


### Steps to reproduce

- Open a documentation page for any node
- Restart Godot

### Minimal reproduction project

NA

EDIT : Added the commit hash @Calinou 
while (p_item->parent && !p_item->E->prev()) {
				p_item = p_item->parent;
			}
			if (p_item->parent) {
				return p_item->E->prev()->get();
			} else {
				return nullptr;
			}
		}
	} else {
		if (p_item->subitems.size() && p_item->type != ITEM_TABLE) {
			return p_item->subitems.back()->get();
		} else if (p_item->type == ITEM_FRAME) {
			return nullptr;
		} else if (p_item->E->prev()) {
			return p_item->E->prev()->get();
		} else {
			
			while (p_item->type != ITEM_FRAME && !p_item->E->prev()) {
				p_item = p_item->parent;
			}
			if (p_item->type != ITEM_FRAME) {
				return p_item->E->prev()->get();
			} else {
				return nullptr;
			}
		}
	}
}
Rect2 RichTextLabel::_get_text_rect() {