SAOCOM Terrain Correction error (SNAP 9.0.6)

I am trying to Terrain Correct SAOCOM L1A Merged products, I have an issue because it seems a metadata is missing slant_range_to_first_pixel, is this a known issue with SAOCOM data, or is this a bug?
The matrices computation seems to work fine,
am I making a mistake in the graph did anyone manage to do Terrain Correction on SAOCOM L1A data which could share the graph they used?
Same error appear with ellipsoid corrections.
I am using SNAP 9.0.6