Yesterday during a Deus UQ run i had a period where i couldn't attack at all after Deus flings the MPA off its core during the map split phase.
I checked if my Nemesis TMG had disappeared, it wasn't but it showed 764/770 required R-atk. After a minute of not being able to do anything i suddenly could use my weapon again and keep fighting. I checked my R-atk stats from weapon requirements and it showed 964 now.
Somehow my mag stats stopped applying after the scene in Deus where it pulls out its wings and keeps its core out.