Gifts of the lotus elite invincibility enemies

[(PSN)civic-cabin4]

So i played gifts of the lotus elite survival steel path mission solo ps5  i don't know if it always happens or if it does reoccur on different missions but could you take a look at it just in case it's not a one time thing 8/5/24

So i was playing solo and i noticed that torment the acolyte came in i defeated torment and then after a while i noticed my weapons dealing zero damage to the corpus enemies like I was dealing no damage they were completely immune no numbers were showing up they would have taken damage if they weren't immune like none of them were taking damage so i was wondering is this a reoccurring thing that can happen because it happened to me and I don't know if it'll reoccur again