Not sure what your intention is, but recall that SV randomization handles only 2-state, i.e. result of randomize() shall be 2-state (not X/Z). Your observation on X after post_randomize() is due to bitwise &, LRM has the below table:
Not sure what your intention is, but recall that SV randomization handles only 2-state, i.e. result of randomize() shall be 2-state (not X/Z). Your observation on X after post_randomize() is due to bitwise &, LRM has the below table: