Putting it our here in case someone else runs into the issue:
I managed to installed with the mamba command once i used: “source /home/ebreard/miniforge3/bin/activate”, but was struggling to activate as mamba activate mfix-24.1 forced me to use mamba init, which did not actually allow me to use mamba activate anyhow; maybe they were conflicts in my bashrc having anaconda3?
I had to do:
(base) [ebreard@login2 ebreard]$ source “/gpfs/home/ebreard/miniforge3/etc/profile.d/mamba.sh”
(base) [ebreard@login2 ebreard]$ mamba activate mfix-24.1
(mfix-24.1) [ebreard@login2 ebreard]$