data = [{"name": 1, "author": "user2", "created":"2023-10-31T12:40:22.083315Z", "attr":...}, {"name": 2, "author": "user1", "created":"2023-10-31T12:40:22.083315Z", "attr":...}...]

To show this data in a tree view I have created a custom model

class Node:
    def __init__(self, data={}):
        self.parent = None
        self.children = list()
        self.data = data
    
    def add_child_node(self, node):
        if node is None:
            return
    
        node.parent = self
        self.children.append(node)
    
    def delete_children(self):
        self.children.clear()
    
    def version(self):
        if self.data:
            return self.data.get("name")
        return None


class MyModel(QAbstractItemModel):
    VERSION = Qt.UserRole + 1
    
    def __init__(self, parent=None):
        super().__init__(parent)
        self.root_node = Node()
    
    def clear(self):
        self.beginResetModel()
        self.root_node.delete_children()
        self.endResetModel()
    
    def add_data(self, data):
        previous_row_count = self.rowCount()
        self.beginInsertRows(QModelIndex(), previous_row_count, previous_row_count)
        for i in data:
            node = Node(i)
            self.root_node.add_child_node(node)
        self.endInsertRows()
    
    def index2node(self, index):
        if not index.isValid():
            return self.root_node
    
        return index.internalPointer()
    
    def data(self, index, role=Qt.DisplayRole):
        if not index.isValid():
            return None
    
        node = self.index2node(index)
        if role == Qt.DisplayRole:
            if index.column() == 0:
                return node.data["name"]
            elif index.column() == 1:
                return node.data["author"]
            elif index.column() == 2:
                return node.data["created"]
            else:
                return None
        elif role == Qt.ToolTipRole:
            if index.column() == 2:
                return node.data["created"]
        elif role == MyModel.VERSION:
            return node.data["name"]
        else:
            return None
    
    def headerData(self, section, orientation, role):
        if orientation == Qt.Horizontal and role == Qt.DisplayRole:
            if section == 0:
                return "Version"
            elif section == 1:
                return "Author"
            elif section == 2:
                return "Created"
            else:
                return None
        return None
    
    def rowCount(self, parent=QModelIndex()):
        node = self.index2node(parent)
        if node is None:
            return 0
    
        return len(node.children)
    
    def columnCount(self, parent=QModelIndex()):
        return 3
    
    def index(self, row, column, parent=QModelIndex()):
        if not self.hasIndex(row, column, parent):
            return QModelIndex()
    
        node = self.index2node(parent)
        if node is None:
            return QModelIndex()
    
        return self.createIndex(row, column, node.children[row])
    
    def parent(self, index):
        if not index.isValid():
            return QModelIndex()
    
        node = self.index2node(index)
        if node is not None:
            return self.index_of_parent_tree_node(node.parent)
        else:
            return QModelIndex()
    
    def index_of_parent_tree_node(self, parent_node):
        grand_parent_node = parent_node.parent
        if grand_parent_node is None:
            return QModelIndex()
    
        row = grand_parent_node.children.index(parent_node)
        return self.createIndex(row, 0, parent_node)
    
    def item_from_index(self, index):
        return self.index2node(index)

The model is created and assigned to tree view, then populated by calling add_data() method whenever new portion of data arrived.

model = MyModel()
tree.setModel(model)
...
model.add_data(data)

This works fine and I have a tree view with three columns filled with information.

But when I try to add sorting by using QSortFilterProxyModel only the first item is shown in the tree, even though the source model is populated correctly.

Am I missing something in my model implementation or doing something wrong?