Ref scrollTop = scrollHeight why is scrollTop not equal to scrollHeight?

Question

JavaScript

Dear, I'm trying to scroll the block to the very bottom after loading the data.
I use useRef and this construction

ref.current.scrollTop = ref.current.scrollHeight;

The block is scrolled, but not to the end
Values ​​are:
scrollHeihgt:
When mounting - 444
After receiving data - 1884

scrollTop:
After assigning - 1440

from here I see that for some reason scrollHeight is minus clientHeight

What's the trouble?

Answer 1

So what's the trouble?
Can't scroll past block boundaries, so scrollTop is cast to the nearest valid value.