Setting up the virtual environment again after reconnecting to e.g. lxplus is not straight forward

When one disconnects from lxplus the environmental variables are lost.

However, as it turns out, these are actually needed to properly set all python paths.

Hence it is necessary to call

setupATLAS
lsetup "root 6.26.08-x86_64-centos7-gcc11-opt"
source myenv/bin/activate
export PYTHONPATH=$VIRTUAL_ENV/lib64/python3.9/:$ROOTSYS/lib

again when restarting the environment after having disconnected.

The documentation should clearly reflect this.