7i76D Spindle Analog output changed overnight!

Hi, This is a weird issue. For some reason analog output of the spindle of my 7i76D has changed overnight. It's roughly giving out twice the correct voltage at the low end and the error gets less at the top (10,000rpm)

This has worked fine since 2021 and I haven't touched any INI, HAL settings. Out of curiosity I measured the 10V power (which is bang on at 10.00V) and the output. If I command 1000rpm its giving out 2.1V which is way above. 0-10,000 rpm spindle (0-10V) It should be at around 1V @1000rpm right?
Never came across anything like this before. 

Is the digital potentiometer in the 7i76 failing? what should I do?