This is a weird issue in Firefox.
Enter a text greater than the width of the input box.
Expected
Input element will reset to the beginning and ellipsis will be shown
What actually happens
Input element stays at the scrolled position and ellipsis does not appear.
If you go to the beginning of the input box, there is a possibility (not sure why) that the ellipsis will be visible when you deselect the box.
Firefox -> 
, 
Chrome -> 
Edge -> 
, 
input {
max-width: 100px;
width: 100px;
white-space: nowrap;
text-overflow: ellipsis
}<input type="text" />