[Users] CCTK_Reduce sum reduction

Dear all,

I am currently encountering some strange behavior when using the CCTK_Reduce "sum" reduction. I observe that CCTK_Reduce would return a global "sum" (=0.06) which is between the global "minimum" (=0.0) and the global "maximum" (=6.6). In the global mode I am calling

CCTK_Reduce(cctkGH, -1, CCTK_ReductionHandle("sum"), 1, CCTK_VARIABLE_REAL, target_var, 1, CCTK_VarIndex("Thorn::source_var"))

Maybe somebody has an instant idea what I should look for to fix this to have the desired summation? Especially, I would be interested in summing up the values only on the finest refinement level. Is there a standard, best-practice way to do so?

Thank you very much and my best

Jens