IfcDiff in Bonsai with Property enabled results in error

I am trying to run IfcDiff in Bonsai. When I am trying to include comparison of properties, I am getting errors.

I am attaching my sample old and new file. I am able to reproduce with various files.
This is my IfcDiff settings:

When running it, I get this error:

    Python: Traceback (most recent call last):
  File "/home/pol/.config/blender/5.1/extensions/.local/lib/python3.13/site-packages/bonsai/bim/module/diff/operator.py", line 165, in execute
    ifc_diff.export(self.filepath)
    ~~~~~~~~~~~~~~~^^^^^^^^^^^^^^^
  File "/home/pol/.config/blender/5.1/extensions/.local/lib/python3.13/site-packages/ifcdiff.py", line 266, in export
    json.dump(
    ~~~~~~~~~^
        {
        ^
    ...<6 lines>...
        default=self.json_dump_default,
        ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
    )
    ^
  File "/home/pol/software/blender-5.1.0-linux-x64/5.1/python/lib/python3.13/json/__init__.py", line 179, in dump
    for chunk in iterable:
                 ^^^^^^^^
  File "/home/pol/software/blender-5.1.0-linux-x64/5.1/python/lib/python3.13/json/encoder.py", line 433, in _iterencode
    yield from _iterencode_dict(o, _current_indent_level)
  File "/home/pol/software/blender-5.1.0-linux-x64/5.1/python/lib/python3.13/json/encoder.py", line 407, in _iterencode_dict
    yield from chunks
  File "/home/pol/software/blender-5.1.0-linux-x64/5.1/python/lib/python3.13/json/encoder.py", line 407, in _iterencode_dict
    yield from chunks
  File "/home/pol/software/blender-5.1.0-linux-x64/5.1/python/lib/python3.13/json/encoder.py", line 407, in _iterencode_dict
    yield from chunks
  [Previous line repeated 1 more time]
  File "/home/pol/software/blender-5.1.0-linux-x64/5.1/python/lib/python3.13/json/encoder.py", line 440, in _iterencode
    o = _default(o)
  File "/home/pol/.config/blender/5.1/extensions/.local/lib/python3.13/site-packages/ifcdiff.py", line 262, in json_dump_default
    return json.JSONEncoder.default(None, obj)
           ~~~~~~~~~~~~~~~~~~~~~~~~^^^^^^^^^^^
  File "/home/pol/software/blender-5.1.0-linux-x64/5.1/python/lib/python3.13/json/encoder.py", line 180, in default
    raise TypeError(f'Object of type {o.__class__.__name__} '
                    f'is not JSON serializable')
TypeError: Object of type SetOrdered is not JSON serializable

I get the same result with Bonsai 0.8.5 and with 0.8.6alpha.

Am I doing something wrong or is this a bug? I would like to compare my two files including changes in properties.

Tom