Wolfenstein: The New Order - profile sharing bugs

How to reproduce:

1. Play the game logged in into Steam account A;
2. Start new game on the same computer logged in into Steam account B to which the game is granted under Steam Family Sharing;
3. Oops...

• Expected result: progress, perks and collectibles are separate for Steam account B, they are also preserved for Steam account A;
• Actual result:
• Progress is reset for account A;
• Perks are reset for account A;
• Collectibles are *not* reset for account B;
• Steam account B gets stats and ranking where existing stats and ranking for account A is a base to which personal stats of account B are added;
• Steam account B gets *some* achievements based on above stats calculation.

At the same time, starting the game on a different computer while logged in into Steam account B yields an empty list of everything (no perks, no collectibles, no stats) *but* erroneous world and friends rank obtained before.

Fallout for Steam account A owner: [at least] can't selectively play game chapters even though the game was already completed.

Lesson: different players must play on different computers, or get really sophisticated about backing up game data, taking risks of likewise sophisticated screwups.