Pasting content from a live article introduces unwanted CSS styling

When I paste content from a live article into the editor, a lot of unwanted CSS styling is inserted into the HTML. This can be hard to spot at first but causes issues with the appearance of the content.

Here's a link to a video demonstrating the issue: https://app.screencast.com/TOcrnqdz38TD0

This is a problem because this CSS that is introduced causes the pasted content to look different from the source content. See the screenshot below:

Original content HTML from the above screenshot:

<h1 id="h_01HPPNPKJV3DWC1V8V2XKBH958">Heading 1</h1>
<h2 id="h_01HPPNPPX87EFZ8VM4597QFEC8">Heading 2</h2>
<h3 id="h_01HPPNPTWM24JE71YQJHJ7GSXK">Heading 3</h3>
<h4 id="h_01HPPNQ1ZBADM3QHSFFZG5KEB6">Heading 4</h4>
<p>Paragraph</p>

Pasted content HTML from the above screenshot:

<h1 id="01HPPNQRYC7F1HFQAE04X8TP1G" style="box-sizing: border-box; font-size: 32px; margin: 0px 0px 0.67em; font-family: -apple-system, BlinkMacSystemFont, ' Segoe UI' , Helvetica, Arial, sans-serif; color: #484848; font-style: normal; font-variant-ligatures: normal; font-variant-caps: normal; letter-spacing: normal; orphans: 2; text-align: start; text-indent: 0px; text-transform: none; widows: 2; word-spacing: 0px; -webkit-text-stroke-width: 0px; white-space: normal; text-decoration-thickness: initial; text-decoration-style: initial; text-decoration-color: initial; background-color: #ffffff;">Heading 1 paste styling original</h1>
<h2 id="01HPPNQRYC5JCCC971GCZRJZ1P" style="box-sizing: border-box; font-family: -apple-system, BlinkMacSystemFont, ' Segoe UI' , Helvetica, Arial, sans-serif; margin: 1em 0px 0px; font-size: 22px; color: #484848; font-style: normal; font-variant-ligatures: normal; font-variant-caps: normal; letter-spacing: normal; orphans: 2; text-align: start; text-indent: 0px; text-transform: none; widows: 2; word-spacing: 0px; -webkit-text-stroke-width: 0px; white-space: normal; background-color: #ffffff; text-decoration-thickness: initial; text-decoration-style: initial; text-decoration-color: initial;">Heading 2</h2>
<h3 id="01HPPNQRYCC2M2A9SMD81PYS6J" style="box-sizing: border-box; font-family: -apple-system, BlinkMacSystemFont, ' Segoe UI' , Helvetica, Arial, sans-serif; margin: 1em 0px 0px; font-size: 18px; font-weight: 600; color: #484848; font-style: normal; font-variant-ligatures: normal; font-variant-caps: normal; letter-spacing: normal; orphans: 2; text-align: start; text-indent: 0px; text-transform: none; widows: 2; word-spacing: 0px; -webkit-text-stroke-width: 0px; white-space: normal; background-color: #ffffff; text-decoration-thickness: initial; text-decoration-style: initial; text-decoration-color: initial;">Heading 3</h3>
<h4 id="01HPPNQRYC3KX7DBWJA4YD88MA" style="box-sizing: border-box; font-family: -apple-system, BlinkMacSystemFont, ' Segoe UI' , Helvetica, Arial, sans-serif; margin: 1em 0px 0px; font-size: 16px; color: #484848; font-style: normal; font-variant-ligatures: normal; font-variant-caps: normal; letter-spacing: normal; orphans: 2; text-align: start; text-indent: 0px; text-transform: none; widows: 2; word-spacing: 0px; -webkit-text-stroke-width: 0px; white-space: normal; background-color: #ffffff; text-decoration-thickness: initial; text-decoration-style: initial; text-decoration-color: initial;">Heading 4</h4>
<p style="box-sizing: border-box; margin-bottom: 0px; color: #484848; font-family: -apple-system, BlinkMacSystemFont, ' Segoe UI' , Helvetica, Arial, sans-serif; font-size: 15px; font-style: normal; font-variant-ligatures: normal; font-variant-caps: normal; font-weight: 400; letter-spacing: normal; orphans: 2; text-align: start; text-indent: 0px; text-transform: none; widows: 2; word-spacing: 0px; -webkit-text-stroke-width: 0px; white-space: normal; background-color: #ffffff; text-decoration-thickness: initial; text-decoration-style: initial; text-decoration-color: initial;">Paragraph</p>

This is causing headaches when we are trying to copy/paste content from other articles. As a workaround, we are forced to paste as plain text and manually re-add any links, bold/italics, bulleted lists, etc. It is unnecessarily time-consuming.

I have contacted support and they seem to not understand or are willing to acknowledge the issue, so I'm sharing here. I would like at least for someone at Zendesk to please acknowledge that they understand what is happening here and that it is a pain point for my team at my company. We should be able to copy/paste content from our own articles without encountering these types of issues.