CASTEP dump wavefunctions during SCF

I am trying to dump the wavefunctions during the SCF cycles in CASTEP Materials Studio 2020. Therefor introduced

num_dump_cycles : 2

in the param file. The castep files states now

dump wavefunctions every                       :          2   SCF cycles

But after 5 SCF cycles still no wavefunction was dumped. I attached the cell, param and castep file.

Any help is appreciated