e53 hard downshift is killin me

[yd_dc]

dear all
first of all let me say hi to all of you members
i have can replicate my problem whenever i want since ive rounded it up:
the car downshift extremely hard (i always think ill leave my tranny on the road behind me whenever the car downshifts ON LOW RPMs, when i ask for some extra power) .
it does not do that when i drive on sport mode or when i keep RPMs high
tranny security mode is always on when the bang occcurs.
any toughts anyone?

i ve had a garagist update the gearbox software

could it be a bad version?
could it be a transferbox failure? FYI the gearbox is new
tkx in advance