When trying to compute the head model, I get this error: (which might be connected to the first problem, I am not sure)
I've also fixed this error occurring when running duneuro for MEG+EEG:
Bugfix: Duneuro MEG+EEG · brainstorm-tools/brainstorm3@3f175a6 · GitHub
Update Brainstorm to get this fix.
For now you should be able to work with the version of iso2mesh you manually downloaded, until we figure out what's wrong with the version downloaded automatically by Brainstorm.