To try and confirm Ryosaeba5554's theory that saves may have been corrupted under Patch 1, I loaded a save on my broken character (post chapter 8, broken for the second time), that was made prior to November 7 (save was Nov 4 - start of Taash recruitment Q).
It has worked flawlessly so far, including doing things I couldn't do before such as:
Hoss wetlands - Gaspin Manor, wolf and evanuris statues, champion chest.
Bunch of stuff in Necropolis and DockLands (including statues in catacombs).
"Forgotton" boss in Necropolis.
What I haven't yet done is finish the Crossroads gates and "that" boss. Another 16hrs til I get back to where I was, I think :)
But so far I'd say Patch 1 breaking stuff seems reasonable. Patch 2 saves seem OK provided character wasn't already broken (it doesn't fix anything that was), and loading a save from prior to Patch 1 seems to be healthy. I'd still hope/expect a "fix" patch to come from EA Bioware (seems like the right thing for them to do) but hopefully this allows folks to progress.
UPDATE 16/11
I completed Weisshaupt and had no problem with any chest or statue. After Weisshaupt, the Dagger is no longer on character's hip but haven't found anything to test it on yet. I could do with a nap. Will report back once I've found something.
UPDATE 17/11
It still works! Found an Evanuris statue, "used" it, at which point the Dagger popped back on my characters hip and it activated successfully. I'm feeling pretty confident this will keep going now.
TL;DR - Loaded a save from before Patch 1 with character created at launch, played from there after Patch 2 (i.e. current patch at time of writing), effectively avoiding any play time or saving while the game was at Patch 1. Dagger is continuing to work as expected.