[2.1.12] (expansion, win64) Lack of achievements on steam

[INteRSteLLar322]

I recently started a completely new walkthrough with no mods other than the original one and space age. The passage was aimed at obtaining achievements, they came in the game, but nothing changed in steam.
I googled the entire internet and forum and couldn't find an actual answer.
Mods are turned off, the console was not used, the settings of the world changed only in the number of resources.
What else could I have done wrong?
(The screenshots show evidence of absence)

[eugenekay]

Please upload the factorio-current.log file from your User data directory from a session where you have earned an achievement in-game (but not received it in Steam).

[Stonk]

I encountered the same issue on 2.1.15, this time in multiplayer on a dedicated server.

What I did
1. Joined a dedicated Factorio 2.1.15 server using the Steam client (Originally started ~ 2 weeks ago on 2.1.14)
2. Finished Space Age by travelling to/past the Solar System Edge at 92:23:29 map playtime.
3. Factorio awarded "Work around the clock" in-game.
4. I exited and restarted Factorio/Steam, but the achievement remained locked on Steam.

What happened
The achievement is shown as earned in Factorio, but Steam did not receive it.

What I expected
Because the game was completed within 100 hours and Factorio awarded the achievement in-game, I expected "Work around the clock" to unlock on Steam as well.

Additional information
- Client: Factorio 2.1.15, build 87284, win64, Steam, Space Age
- Map version: 2.1.15-2
- Scenario: freeplay
- Map playtime at completion: 92:23:29
- Multiplayer dedicated server (Linux, Docker)
- Loaded mods shown by the save and log are only the official components: base, elevated-rails, recycler, quality, and space-age, all version 2.1.15.
- The client log confirms that the Steam API initialized and that the game was running on the selected Steam version branch.
- Public Galaxy of Fame proof: https://factorio.com/galaxy/Iron%20I:%20Iota4-6.G2Z4
- The Galaxy entry records completion at 92:22:38 on Factorio 2.1.15 with 5 players and exactly the five official mods listed above.
- Steam's stats_log.txt records `CAPIJobStoreUserStats::BInit() - no upload needed` for AppID 427520 around the relevant sessions; it does not show a failed or rate-limited Factorio stats upload.
- Restarting Factorio and Steam did not synchronize the achievement.
- Loading the save in Singleplayer and travelling to Galaxy's edge again did not award it either.