it seems the Xperia 10 II (seine) required binary build is missing from sony completely , aka 10.0.7.1_r1_v12b_seine.zip dont exist.
when you go to the “Android 10.0 – Kernel 4.14 – Seine (latest)” it downloads the “10.0.7.1_r1_v10a_seine” version instead even when it says on the site “*10.0.7.1_r1_v12b_seine”
*
at times the download doesnt work at all, it gives a correct version but empty zip file