I am having an issue when evaluating SAR results in Sim4Life.

When I try to view the SAR result (e.g., psSAR IEEE/IEC 62704-1 Avg.SAR(x,y,z,f0)) over the original simulation domain, Sim4Life reports an error indicating that the grid is too coarse, and I cannot obtain the SAR result.

However, if I first use Crop to reduce the analysis region to a smaller area around the region of interest, the SAR evaluation works and I can successfully visualize the SAR distribution.

The underlying simulation results and grid remain unchanged; I am only changing the spatial region used for post-processing.

Could you please clarify why cropping the analysis region changes whether the SAR evaluator considers the grid sufficiently fine?

In particular:

Could a coarse-grid region somewhere outside my region of interest cause the SAR evaluation for the whole domain to fail?
If the SAR result becomes available after cropping out those regions, can the SAR values within the cropped region be considered valid, or should I refine the simulation grid and rerun the simulation?

Thank you for your help.