[2023] New multiplayer character after account creation

I have a multiplayer game running where we've just started the rocket (my first time after 180h and 13 on this save). Unfortunately I've created a Factorio account just before we launched the rocket to install mods, and now I'm recognized as a new character. Thus I didn't get any achievements. Is there any way to load the save with the original character or disable the 50% participation restriction? Logging off in the settings didn't work.