Z axis screw (or motor) is making a clunking noise)

I have an Ender V3 with CR Touch. I have not used it in a while but when to use it the other day and things not working.

Long story short, whenever I try to print or use the Auto Home function, when the Z nozzle hits the Z axis sensor I get a horrible clunking noise. When I look at the Z axis motor andZ axis rod you can see it do a small turn in 1 direction and a small turn in the other direction almost as if it is trying to move further down on the Z axis but it is hitting something.

Does anyone have any idea of what is going on.I can, if necessary, attach a recording if it helps.