I also had the same issue, here's a save with Allie logged out right where the Hedge Ascent is, I've been forward and backward through the area hundreds of times specifically looking for a trigger zone, and it's just not popping.
https://www.dropbox.com/scl/fi/u5p30lt638mgipediezmd/Hedge-Ascent-Bug.zip?rlkey=pvb3knkt2iidifn8jzsjafh7y&dl=1
Let me know if you need additional files.
I'm in the exact same state as OP, and I about died when you fixed the sandbox bug and not this. After the latest patch, it's pretty clear you aren't aware that it's impossible to 100% on a new (or late 2022) save.