Geotiff via Export_Elevation showing 0 values outside Polygon Crop

Hi,

I am using the following line of code and on some geotiffs all data outside my polygon crop is empty area (as i want). On others, the geotiff is aligning data as a 0 elevation value outside my polygon crop. Is there a way to force delete areas outside the polygon crop?

EXPORT_ELEVATION FILENAME="%MASTER_FOLDER%%PARENT_DIR%_cropped.tif" TYPE=GEOTIFF POLYGON_CROP_NAME="Crop-TSF-Border" ELEV_UNITS="METER" FORCE_SQUARE_PIXELS="YES" SAMPLE_TYPE="U32" FILL_GAPS="NO" BG_TRANSPARENT="YES"