Apparently not. I am still stumped in trying to find out how to fix it in UE5.1, even despite following the tutorial for launcher builds. A similar issue happened with UE4 years ago and the only way I recalled fixing it required I downloaded a custom engine build just to do so. Considering how heavier UE5’s custom builds are and with my morale and trust with Epic Games butchered, I simply lack the patience to go through such an uphill battle again, much less solely to get Steam achievements to work.
At this point, I’m just going to have to consider that journey forfeit and just avoid achievements for my remaining UE games entirely.
Maybe Godot or some other engine will fair better.
PS: It is also not a surprise that Epic Games hates Valve and their Steam platform, so perhaps this could play a factor into why there is increasing less care for Steam’s features now. They have Epic Games Store now, that’s where their priorities are at.