After doing this with 18 characters, this is what I have found.
When going up the hill to grab the Sword Hilt, she has a tendency to despawn while on the way through it, enemies or no enemies she suddenly stops following and disappears. Relogging does fix this issue, I usually do it at her meeting spot where you talk to her to go to the next trial; this happens with 1 in 3 of my characters that I've done it.
On the way to get the staff going to the left side, there's a point along the way that seems to force all your pets, companion, and Isobel to despawn. Also relogging while at the barrier fixes this issue, have to resummon my pets and companion manually though. It doesn't just affect pet classes, they're most noticeable with I don't have my bear or twilights flapping about. This is not as common, 1 in 5 characters experienced this.
At the barrier, the center Pillar is hard to interact with as you have to contend with the barrier and Isobel standing fairly close to it. I think all 3 interact points are fighting for priority making it difficult to position getting the hit. It's more prominent after retrieving the items, the hit box is even smaller and you have to really angle yourself with very light change in position to interact with it.
Edited by phaneub17_ESO on June 9, 2022 3:26AM