BulkFS_calc=T for 3D Fermi surfaces

Dear all,
I am trying to generate a 3D Fermi surface of bulk iron. I have a wannier90_hr.dat Hamiltonian that reproduces very accurately the bulk band structure when I use BulkBand_calc=T. When I set in addition BulkFS_calc=T I get the FS3D.bxsf file, but in this file, the bands have no bandwidth, as if only the value of the band at one k point was taken into account. However, I am using:

&PARAMETERS
Nk1 = 101
Nk2 = 101
Nk3 = 101
/

which should be enough to produce the correct bandwidth. Also, the bands in bulkek.dat look perfect and with the right bandwidth, so the problem is not in the Hamiltonian wannier90_hr.dat and for some reason WannierTools is not producing a correct FS3D.bxsf.

Do you have any suggestions about what I might be doing wrong?

Thank you very much!
Irene