I have used Sentinel 2 data to retrieve Red Edge indices in SNAP and found discrepancies in the resultant raster (attached). The inconsistencies pertaining to NDVIre3 from Sentinel 2 involves following equation;
Reference to these indices: https://www.sciencedirect.com/science/article/pii/S0303243416300368?via%3Dihub
Prior to use Band Math, the atmospheric correction was performed and indices were calculated on Scaled reflectance and same pixel size. I have also used QGIS to cross check the results but found same noise in the resultant image. On the contrary, NDVI (B8-B4) / (B8+B4) produces smooth raster realistic to ground realities. I am not sure what might be the cause of this problem.