Hi, while we understand the frustration, it would help greatly if you can provide an example with logging attached so we can determine what your specific issue is and work toward a solution.
Hi. Are you disconnecting the AP via the button on the MCP (the panel where the AP buttons are) or via the AP disconnect on the control stick.
The latter is the preferred method with one click used to disconnect and a second to clear the alarm.
You don't need to but its avail as an option.
Regardless, BBJ0987 is correct in that it's most likely an errant binding that is inadvertently moving your rudder a few degree causing the AP to compensate.