SNAP 8.0 unfortunately have the same issue. Using ALOS PALSAR 1 PLR 1.1 Product after Deskewing, Multi Looking, Polarimetric Spekle Filter and Terrain Correction. I’ve tried to use PolSARPro 6.0 Biomass Edition but I wasn’t able to create poligons using the image without T3 geocoding. During T3 Geocoding and error occurs and the image does not look good, in correct geometry.