I am also experiencing a similar/same problem. I have DA:I GOTY edition on 3 different platforms (Steam/PS/XBOX) and I actually haven't played the GOTY edition at all anywhere before (finished it on X360 when it first came out, base version)
So my problem is like this: I downloaded the DA:I GOTY edition from Steam, no problems. All the DLCs seemed to have been downloaded too. EA App recognizes that I accessed the version through Steam no problem, when I look at my add-ons I see that EA App also recognizes that I access them through Steam, so far so good. I was merrily playing my game but at around 60h point I've realized that I should've encountered at least one of the pre-ending DLCs. Then I realized I didn't have any of the items and stuff. At this point, I've realized that I do not have any of the DLCs (missed war table rewards and all) Tried to figure out why this happens and found out about this mod.
This mod/fix definitely works but it also deactivates all of the online features. I realize that online features don't mean much at this point but still. If you log in after fixing the game your save doesn't load up and when you try to load it it tells you "You need to install/own DLCs." It's kind of annoying and sad that this problem existed at least since 2021 and wasn't fixed.
I also tried to download the game from EA App instead of Steam but then EA App tells me I own the standard edition and none of the DLCs. For some reason, I cannot find the game on the store too (Turkey) The game + DLCs are all available in any other store you can think of.
My only concern is about carrying over saves/choices to the new game. I know that we'll be able to carry over our choices somehow, and we likely won't use the Keep (I follow the updates) While this fix definitely works, not being able to synch the game with the Keep is kind of annoying & sad. Just wanted to let the team know about the situation -which you probably are aware.