`quarto preview` on a website project not watching resources on repeat previews

Bug description

I'm noticing very inconsistent resource hot reload in quarto preview.
Steps reproduce on my Ubuntu machine.

I think that watch is not working where files already present in the _site folder are recycled - this or something cache-related perhaps.

Steps to reproduce

git clone https://gitlab.com/declann/quarto-issue-parent-resource-locations.git
cd quarto-issue-parent-resource-locations/website
quarto preview
# edit website/resources/umd.js e.g. in a separate shell in website location run:
echo "// hello" >> ./resources/umd.js
# my result: here I get a hot reload
# cancel quarto with ctrl+c
quarto preview
echo "// hello" >> ./resources/umd.js # in website location
# my result: here I don't get a hot reload

Expected behavior

I expect consistent hot reloads whenever umd.js is modified.

Actual behavior

In first instance of quarto preview I get a hot reload, in follow ups I don't.
Appears perfectly repeatable on my Ubuntu machine.

Your environment

quarto 1.4.451
Ubuntu 22.04.3 LTS

Quarto check output

Quarto 1.4.451
[✓] Checking versions of quarto binary dependencies...
      Pandoc version 3.1.8: OK
      Dart Sass version 1.55.0: OK
      Deno version 1.33.4: OK
[✓] Checking versions of quarto dependencies......OK
[✓] Checking Quarto installation......OK
      Version: 1.4.451
      Path: /opt/quarto/bin