Thanks a lot, Florian. I am sorry that I missed the two different conventions.
You are right. If I take Tu(3,3)=-3150.0, spectrum file gives Yt=0.8286 and
this makes At around -3800 with the resulting Higgs mass ( 122.7) around
FeynHiggs value (124.4).
However, Yb is very different from FeynHiggs at the input scale.
Best regards,
Jyotiranjan