Go to you Steam Library, Right-click Bannerlord, go to properties. In the BETAS tab, there is a dropdown of all patches. Select the one you want, and the game will either update or roll back to that patch. When it is not the current updated build, it will stick with the build you choose and not update when an update appears (it will only say there is an update queued when one is available), so you can keep playing on the most stable patch for you. Note that this may disable your ability to play multiplayer because you are not using the most up-to-date patch.