Hello, it is sometimes that I have this behaviour:
when I use repeatedly a zle widget like kill-word and then I use yank to
restore the killed text, only the last killed word is returned.
I remember that all the consecutive killed word were returned at once, and
the manual support this:
[...] When repeatedly invoking a kill widget, text is  appended  to  the
 cutbuffer instead of replacing it[...]
Is it possible I deactivated this behavior somehow?

the manual says also "when wrapping such widgets, it is necessary to call
`zle -f kill' to retain this effect" but I am not wrapping them

Pier Paolo Grassi