incremental search and highlight all matches stops working with existing highlight

[kting28]

Hard to describe in words please see gif below. In general, with wilder's / and ? matching enabled, nvim's incremental highlight is disabled if there's an existing search highlight.

The initial search of /test has incremental highlight. After hitting return, the next search /est has no incremental highlight. In nvim without wilder, every new search has incremental highlight.

Is this intentional ?

[kting28]

I found the workaround apply_incsearch_fix enabled would fix this issue. But it breaks the <Up> <Down> arrows in / mode. After trying a few things I found that changing the line below to noh instead of feedkeys fixed the issue.

function! s:redraw(apply_incsearch_fix, is_redrawstatus) abort
  if a:apply_incsearch_fix &&
        \ &incsearch &&
        \ (getcmdtype() ==# '/' || getcmdtype() ==# '?')
    noh  "This restores the incsearch in all cases
    return
  endif

The problem is that when / is first pressed, the initial match suggestions are no longer shown. But this is not an issue for me ..