Requiem Shard

Apparently, there is an area near the old cannibal fort where you are unable to use perks such as evasion and confidence as "casting" is blocked. Is this intentional?

I believe I've seen confirmed elsewhere that casting 'deadspots' is intended and usually around specific areas where I assume there is a lore reason for it. I've seen those skills brought up as counting as casting before. I can't imagine they should be affected by those 'deadspots', however.