There’s a delay on event triggers caused by a conflict I’ll be fixing – this means all events (such as ambush fights etc) that should trigger instantly instead lag for a few seconds. Once you’ve found your 4 items here (which are all in there somewhere!) you’ll get the message saying to leave. To trigger this event, wait on where the bloodstain is by the door and that should allow you to progress before the fix at least.
That part was bugged but should now be fixed in the newly uploaded HotFixes V2 – however it may have locked you into that area as a result of going there before the fix. If you can re-load back before then do so and it will now work as it should, otherwise I can upload a slightly modified version of this mission to fix this issue for you specifically – so please let me know thanks.
