Ok. For science.
i did not have a close enough save to see if the venatori altars made THE difference but i loaded a temporary chapter save right before the cutscene of “someone” returning after the events after getting the last two companions (sadly 3 hours of exploration gone if i continue this save). Both altars I mentioned worked PRIOR to doing the venatori sealed ones. I will go back to those to see if those work after the Elvhenan Haven and Hoarfrost Reach (not its actual name) ones are done now….and rushed to them and they both work too.
so some things i did in those three hours are exploring most of Rivain Coast available to me except the side quest about the first qunari warden, the first companion quest of Taash and 10 rounds at the Hall of Valor… so not sure if any of those matter in triggering the issue 🤷♂️
i had also noticed that the entire Library in the Lighthouse is empty (no decor, no bookshelf, etc). Though I did see this earlier in the game without any repercussions. So uncertain if related to this issue and/or the memory locations on the Library walls. 🤷♂️🤷♂️🤷♂️