If you move the mouse and exit an UI, the player will rotate to the position of the mouse at the moment the UI is exited. This has been observed in Chests, Large Chests, Hoppers, Droppers, Crafting Tables, Furnaces, Blast Furnaces, Enchanting Tables, Ender Chests, Anvils, Shulker Boxes, Signs, etc. I can assume this extends to Job Site blocks containing a UI, as well as any other items with a UI, including the Game Menu.

To reproduce the issue, enter any in-game interface. Move the mouse, and exit the UI (escape key) WHILE the mouse is maintaining motion. If the mouse movement is stopped shortly before exiting the UI, the player will maintain the existing rotation with no change.