Pandas version checks

  • [x] I have checked that this issue has not already been reported.

  • [x] I have confirmed this bug exists on the latest version of pandas.

  • [ ] I have confirmed this bug exists on the main branch of pandas.

Reproducible Example

import pandas as pd

df = pd.DataFrame(
            {
                "a": [4,2,3,None,1,2,3],
                "g": [1, 1, 1, 1, 1, 1, 1],
            }
).convert_dtypes(dtype_backend='pyarrow')
df['i'] = 1

print(df.groupby('g')['a'].transform('cumsum', skipna=True))

Issue Description

On linux i get

0       4
1       6
2       9
3    <NA>
4      10
5      12
6      15
Name: a, dtype: int64[pyarrow]

on window:

0       4
1       5
2       8
3    <NA>
4       9
5      11
6      14
Name: a, dtype: int64[pyarrow]

Expected Behavior

same on windows and linux

Installed Versions

INSTALLED VERSIONS ------------------ commit : 4665c10899bc413b639194f6fb8665a5c70f7db5 python : 3.11.9 python-bits : 64 OS : Windows OS-release : 10 Version : 10.0.26100 machine : AMD64 processor : Intel64 Family 6 Model 141 Stepping 1, GenuineIntel byteorder : little LC_ALL : None LANG : None LOCALE : English_United Kingdom.1252 pandas : 2.3.2 numpy : 2.3.3 pytz : 2025.2 dateutil : 2.9.0.post0 pip : None Cython : None sphinx : None IPython : 9.4.0 adbc-driver-postgresql: None adbc-driver-sqlite : None bs4 : None blosc : None bottleneck : None dataframe-api-compat : None fastparquet : None fsspec : None html5lib : None hypothesis : 6.140.2 gcsfs : None jinja2 : 3.1.6 lxml.etree : None matplotlib : None numba : None numexpr : None odfpy : None openpyxl : None pandas_gbq : None psycopg2 : None pymysql : None pyarrow : 21.0.0 pyreadstat : None pytest : 8.4.2 python-calamine : None pyxlsb : None s3fs : None scipy : None sqlalchemy : None tables : None tabulate : None xarray : None xlrd : None xlsxwriter : None zstandard : None tzdata : 2025.2 qtpy : None pyqt5 : None

Comment From: MarcoGorelli

maybe related to https://github.com/pandas-dev/pandas/issues/61896