This package is a sample kit of Client Side Web Parts built on the SharePoint Framework SPFx. You can find here different kind of high visual web parts as carousel, images galleries, animations, map, editors, etc.
Firstly, downloaded and deployed the production "sppkg" file, added the rss-feed webpart to the page and the browser-console displays the workbench viewer "WARNING" & disclaimer.
Second, rss-feed fails with the following error explanation in console "A preload for 'https://spfx40fantastics.azureedge.net/spfx40fantastics/spfx-40-fantastics-rssreaderstrings_en-us_dae2e06da398c5053e1d915cb00f2eb3.js' is found, but is not used because the request credentials mode does not match. Consider taking a look at crossorigin attribute."
It seems that the source code needs a tag property similar to <script type="module" crossorigin="anonymous">
I've just had one of our users report it as it can affect other web parts on the page when in Edit Mode. i.e. some of the Text web parts appear blank when the Accordion web part is on the page.
A preload for 'https://spfx40fantastics.azureedge.net/spfx40fantastics/spfx-40-fantastics-rssreaderstrings_en-us_dae2e06da398c5053e1d915cb00f2eb3.js' is found, but is not used because the request credentials mode does not match. Consider taking a look at crossorigin attribute.
"It seems that the source code needs a tag property similar to
<script type="module" crossorigin="anonymous">