Mode: Singleplayer
Important: Only female characters
Generally
When sitting in the saddle, the breasts change to default size.
Getting on and off the horse fixes other breast bug. 
Horse bug description
- After getting on the horse, the breast size changes to default values.
- While riding, the breasts do not animate (do not bounce).
- The bug is only present when riding a horse, after getting off it everything returns to normal.
Breast bug description
- After entering the game, breasts do not animate (do not bounce).
- The bug I describe occurs only in singleplayer mode.
- The bug occurs in the Live and Testlive game.
Reproduction methods:
- Make sure you play on an old save game where you have a lot of construction and followers. Just get in the singleplayer game. If your character is near a larger construction, breasts will not move.
- Turn on several programs that will run in the background and/or force the game to run on only one processor core. Then start the game. Depending on your computer’s power, breasts may not animate even when you create a new singleplayer game.
Description of ways to fix the bug:
- Only Testlive game: Get on the horse and dismount. It works in 100% of cases.
- Live and Testlive game: Exit to the main game menu and load the game again.
- If that doesn’t work, leave the character away from all constructions and followers. Then exit to the menu and try again.
- This method works only sometimes, usually you have to go to the menu several times.
- Live and Testlive game: Take off your bracelet or die. It works in 100% of cases.
Related bend bug (fixed)
- Live game: After entering the game, the character cannot bend.
- Live game: The bug always occurred when the breasts did not move.
- The bug prevented collecting some resources and fighting with some opponents (if they are too high or too low).
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Important: Testlive game: In the Testlive version, the bug does not occur at all.
Description of ways to fix the bug:
- The bug was fixed by the same methods as the breast animation bug.
- Important: In the Testlive version, the bug does not occur at all.
Source of breasts and bend bug
Probably the character loads too quickly and gets the values of the map that has not yet been fully loaded. In this situation, the animation subsystems may get incorrect data and stop working properly.
If the bones (breast) connected to the character by a chain method get too high values, it can trigger a break command and stop working at all.
Some physics functions require to get all values immediately, after creating the object, if there are several such objects and they want to get the values from each other, only the last will get all correct values. Therefore, all newly appearing player characters work without problems.
Partially related stoops bug (fixed)
I also did not notice the bug on the Testlive, when the player’s character stoops (after climbing the next floor using the stairs) using the controller (gamepad) to move.
Bug screenshot
- If the character could not bend (and the breasts were not animated) this error did not occur at all.
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Important: In the Testlive version, the bug does not occur at all.
Summary
I just count on repairing the size of the breasts while riding a horse. 
The bending and stoops bug was corrected when changing the movement/dodge system. Lack of breast animation can be repaired by getting on and off the horse or committing suicide 
(in the game), so you can try to fix it some other time… 
Thanks for reading. 
You did a great job fixing all these bugs - consciously or not. 
I tried to show a full picture of this matter. It’s really amazing how one bug can be a remedy for another problems. 
Some of them were not even reported because they were deep consequences of other issues. 
