Dear Francois,
This is an exported Brainstorm protocol with one patient, whose brain model is co-registered for group analysis. I selected the file I'm referring to in the screenshot below. This is the 'Group analysis' connectivity that is not plotted correctly.
The .zip file can be found here: Paper1_PN07_copy.zip - Google Drive. For some reason I couldn't load it in Brainstorm while archived, but it worked after extracting the files.
Please let me know if I can provide anything else, and thank you so much for all the help!