Hi and welcome to Arturia forums.
A operator Pan is deactivated when the selected operator is'nt linked directly to the output in the selected Algorithm. That mean all operator Pan's only are availble for Algoritm number 32.
I can suggest you read the manuals sections:
6.5.4. Pan
Use this parameter to set the stereo position of the operators. The Pan knob is only available
when one of the carriers is selected.
6.3.1. Disabling an oscillator - That include this info: The pan position of a carrier with a disabled oscillator will also be applied to the modulators.
Hope that's it.