Something isn't right. When I run the notebook before using this task I get

for the 2nd and 3rd plots in the notebook, but if I use the notebook contained in this ticket I get

when run on the same data.
The task command that I used to merge the catalogs was
pipetask --long-log run -b /repo/dc2 --output-run "u/fred3m/DM-32436/DC2_44/20211210T214832Z" --extend-run -d "instrument = 'LSSTCam-imSim' and tract in (3828,3829) and skymap='DC2'" -p /project/dtaranu/dc2/match_catalog_pipe/match_tract_catalog_probabilistic.yaml --input 2.2i/runs/test-med-1/w_2021_44/DM-32391,2.2i/truth_summary --no-versions
Fred Moolekamp, can you see if this works for you without having to setup/install gauss2d/(meas_extensions_)multiprofit? I tested by including only modelling_research in my PYTHONPATH and it seemed to work.
If you need to compare, I have w44 and w40 notebooks (the latter in an old subdirectory since it won't work as-is anymore).