It seems that cut is replacing Space Char with a Tab Char when you use the special function -w for delimiters
Fast proof could be a
ls -al | cut -w -f x- (where x the field number)
you will get someting like
filed-x <TAB> field-x+1 <SPC> field-x+2 <SPC> ...
filed-x <SPC> field-x+1 <SPC> field-x+2 <SPC> ...
You could verify it with hd(1) where you see 09 for <TAB> and <20> for SPC
Expected behaviour would be, that cut is not touching/changing the field delimiter