python3-lxml package is present in Sdk 41 but not in Platform
On version 40 lxml python module was present in both the Sdk and Platform runtimes but its missing from Platform 41
[📦 org.gnome.Sdk ~]$ ls /lib/python3.9/site-packages/
cairo libxml2.py pip-21.2.4-py3.9.egg-info setuptools
Cython lxml pkg_resources setuptools-58.0.4-py3.9.egg-info
Cython-0.29.24.dist-info lxml-4.6.3-py3.9.egg-info __pycache__ six-1.16.0-py3.9.egg-info
cython.py mako pycairo-1.20.1.egg-info six.py
_distutils_hack Mako-1.1.5-py3.9.egg-info pygments wheel
distutils-precedence.pth markdown Pygments-2.10.0-py3.9.egg-info wheel-0.37.0-py3.9.egg-info
drv_libxml2.py Markdown-3.3.4.dist-info PyGObject-3.42.0-py3.9.egg-info xcbgen
gi meson-0.59.1.dist-info pygtkcompat
libproxy.py mesonbuild pyximport
libxml2mod.so pip README.txt
xjuan@Ryzen:~$ flatpak run org.gnome.Platform//41
[📦 org.gnome.Platform ~]$ ls /lib/python3.9/site-packages/
cairo libxml2mod.so pkg_resources setuptools
_distutils_hack libxml2.py __pycache__ setuptools-58.0.4-py3.9.egg-info
distutils-precedence.pth mako pycairo-1.20.1.egg-info six-1.16.0-py3.9.egg-info
drv_libxml2.py Mako-1.1.5-py3.9.egg-info PyGObject-3.42.0-py3.9.egg-info six.py
gi markdown pygtkcompat xcbgen
libproxy.py Markdown-3.3.4.dist-info README.txt