Using 'temperature' as a design variable breaks calcVal functionality

I'm using the calcVal function to use a found trim value from my first test in a second and third test and it works as expected. I've added a fourth test that creates a design variable called temperature and I'd like to set it using the calcVal function output of my second test. For some reason though this breaks the calcVal function in the second two tests. If I disable the fourth test everything works again as expected.

If I enter a hard coded value for temperature in the fourth test then it still breaks the calcVal functionality in the second and third test.

Is this a bug or am I missing something?

I'm using Cadence version IC6.1.8-64b.500.9.