A couple days ago, I wanted to play DAI through Heroic(flatpak) on linux (gnome/debian 13), i own the game on EpicGames. I installed it through the heroic library and it installed the EA launcher. it didn't automatically install the game through EA nor launch the EA launcher after, so i manually ran the EA launcher through the "run on prefix" option in settings and then logged in and installed the game. (first time i let it install in default place, second time i had it install on X:/Games/Heroic/ with all the other heroic games hoping maybe that would fix the issue. it didn't)
The game installed through EA, but the heroic library play button would "launch" "playing" and then return to "play" with nothing happening whatsoever. I tried pressing play with EA running in the background but it still wouldn't launch. I manually pointed to the DAI EXE, but wouldn't launch either. I tried launching it through EA but it wouldn't launch there either claiming "error on their side".
looking it up, i realised the issue was that EA was looking for Epic Games confirmation that i own the game but since heroic won't keep the Epic Games redists running, it won't launch the game. I went and installed Epic Games in the prefix and had both Epic Games and EA running and then launched it from either platform and the game runs. However the won't launch through Heroic at all still. I tried pointing it to the EA Desktop EXE but it wouldn't launch it, only running it on prefix manually does.
Worse yet, having the game running through EA+EpicGames on the prefix means the game won't detect controller input, only kb&m.
How do i fix this? alternatively, Is there a way to manually force heroic to run the epic games redists /game controller stuff on the prefix so that i can launch the game & use controller?