I was checking the forums just because I have encountered the same issue with PC Steam/PS5 crossplay.
Until September 9, everything worked fine. Then I played on PC only for a couple of days, and now my PS5 won't download anything from Larian's cloud (which is up to date with my Steam saves).
I tried unlinking and linking my PSN account, but it didn't help.
It looks like a server-side issues, are the devs aware of this?
Cheers
