quick question is psychic scream supposed to effect allys. I noticed when i was playing as orks with my mate that i was having major moral issues even for orks and noticed his scream was impacting me.
Is this working as intended or a bug?

Sounds like its not working as intended at all. The debuff should not affect allies

I guess it make sense in some way, unless Tyranid have ability to tune their psychic scream not to affect specific others, but yes this seems like omission on gameplay perspective.