CryoTrap temperature is not stable, what you be the problem.
Problem with unstable CryoTrap temperature at low and high temperature.
The left picture shows clearly big noise at both high and low temperature. The picture in the right shows normal behaviour.
Here the LN2 valve was leaking during the close state.
After replacement of the LN2 valve the problem is gone.
Part Number: 2406-4306 LN2 Cryogenic Solenoid Valve Assembly