Grepper in Vimscript function does not execute subsequent cdo command

I am writing a simple function to search the word under cursor and replace it automatically, something along the lines of
```
function! Replace() abort
Grepper -cword -noprompt -noopen
silent execute "cdo s/" . expand("") . "//g"
endfunction
```
however, I noticed that when using `vim-grepper` and `Grepper` as grep wrapper, the subsequent `cdo` command is not executed, namely the quickfix windows opens up and no replacement is done. If instead I use the standard `vimgrep %` with the above function all works as intended.

I suppose it may have to do with having to use `(GrepperOperator)` in a function rather than `Grepper` as command, or am I making some other trivial mistake (for instance there are flags to directly execute `cdo` commands after grepping)?

Start at the implementation of the `Grepper` command and trace how it populates the quickfix list before the following `cdo` runs. Reproduce the function with `Grepper -cword -noprompt -noopen`, compare it with `vimgrep %`, and verify that the replacement executes after the quickfix results are ready.

Written by the indexing model from the issue text.