Full error trace:

pfs, sp = pfs.generate_staypoints(method='sliding')
Traceback (most recent call last):
File "/usr/local/lib/python3.9/site-packages/IPython/core/interactiveshell.py", line 3550, in run_code
exec(code_obj, self.user_global_ns, self.user_ns)
File "", line 3, in
pfs, sp = pfs.generate_staypoints(method='sliding')
File "/usr/local/lib/python3.9/site-packages/trackintel/model/positionfixes.py", line 100, in generate_staypoints
return ti.preprocessing.generate_staypoints(
File "/usr/local/lib/python3.9/site-packages/trackintel/preprocessing/positionfixes.py", line 101, in generate_staypoints
pfs = positionfixes.copy()
File "/usr/local/lib/python3.9/site-packages/trackintel/model/util.py", line 14, in wrapper
result = func(self, *args, **kwargs)
File "/usr/local/lib/python3.9/site-packages/trackintel/model/util.py", line 65, in copy
return super().copy(deep=deep)
File "/usr/local/lib/python3.9/site-packages/geopandas/geodataframe.py", line 1535, in copy
copied = super().copy(deep=deep)
File "/usr/local/lib/python3.9/site-packages/pandas/core/generic.py", line 6813, in copy
return self._constructor_from_mgr(data, axes=data.axes).finalize(
File "/usr/local/lib/python3.9/site-packages/trackintel/model/util.py", line 55, in _constructor_from_mgr
return self._constructor(GeoDataFrame._constructor_from_mgr(GeoDataFrame, mgr, axes))
File "/usr/local/lib/python3.9/site-packages/trackintel/model/util.py", line 43, in _constructor_with_fallback
result = GeoDataFrame._geodataframe_constructor_with_fallback(*args, **kwargs)
AttributeError: type object 'GeoDataFrame' has no attribute '_geodataframe_constructor_with_fallback'

Hi! Apologies for the delay - I just saw this, and many thanks for the reporting!

The error originates from the fix in #646, due to a change in a later version of geopandas. I can confirm the method works for geopandas >=1.1.0. This geopandas dependency is also now reflected in our requirements file.