Without seeing the code all I can say is somewhere in some CSS file being loaded in your site, there is something that may look like:
... li { list-style: ...}
or
... li { background: ... }
and that is applying the arrow you see. Without a link to the site in question, there’s no way to get a solid answer as to what exactly you need to look for and change.
Ok it has something to do with the Page Builder by SiteOrigin plugin, if I deactivate it the problem disappears. I would prefer to keep the plugin though as it makes some things easier for me…
You can manually add bullets using the text editor. Here’s an example.
<ul>
<li>Line 1 </li>
<li>Line 2 </li>
<li>Line 3 </li>
</ul>
It will show like this:
On your page it is placing the <ul><li></li></ul> on each and every line.
<ul>
<li>general cleaning (metal and wood), oiling and hydrating</li>
</ul>
<ul>
<li>changing or refubrishing old or leaky pads</li>
</ul>
<ul>
<li>replacing thread or cork on the tenons</li>
</ul>
<ul>
<li>replacing cork stopper</li>
</ul>
<ul>
<li>replacing broken springs</li>
</ul>
<ul>
<li>cracks fixing</li>
</ul>
<ul>
<li>reshaping damaged embouchure hole</li>
</ul>
<ul>
<li>retuning of individual notes (only on historically non-relevant flutes)</li>
</ul>