If you fix the Pitch axis exclusively at +90 degrees, Yaw and Roll become mathematically degenerate (Gimbal lock). The "Live View" will suddenly flip. A robust implementation must detect this and temporarily break the "Exclusive" lock or switch to a quaternion slerp that respects the fix.
—a function that uses the rear LCD to display exactly what the sensor sees in real-time. However, high-resolution processing can lead to axis-related synchronization errors. The live view axis fix exclusive