When powered off mine falls quite rapidly sometimes (enough that I have a foam block to put underneath now to prevent it from crashing on the bit)
However what I didn’t understand was why it was only happening on 1 side but the other side was staying up. It wasn’t until I left the x axis on the middle and cut power that I clued in. The weight wasn’t balanced and basically it was crashing on whatever side had the router. If it was x=0 it would come down on that side. If it was at x=max it would come down on the other side. If it is mostly centered it will come down evenly and at a slower speed.
Edit: If it is while homing on Z and then the Z crashes on whatever side has the router I had to add 2 resistors to the bottom of the motherboard…
This is the origional thread that pointed me to that solution