Copy and paste code corruption

Steps to reproduce bug:

  1. Select some text in one HTML document, and copy (using Command-C shortcut).
  2. Choose Edit > Show Clipboard, and verify that the clipboard contains nothing but a simple text string.
  3. Select text in another HTML document, and paste (using Command-V shortcut).

The result is a whole lot of cruft being added to the code along with the text. What should be just text, looks like this:

<h4 spellcheck="true" data-medium-editor-element="true" role="textbox" aria-multiline="true" data-medium-editor-editor-index="6" medium-editor-index="378915f7-0b2f-3c9e-d1b8-0c316c5caeea" data-placeholder="Type your text" data-medium-focused="true">TEXT IS HERE</h4>

The h4 tags were added too, so now there are nested h4 tags, along with the rest of it. This doesn’t happen every time I copy and paste something, but often enough that I simply can’t rely on it. If I carefully select the actual text in the code view, paste works fine—but then I may as well just be hand coding in a text editor.

I’m running Pinegrow 5.41 on macOS 10.14.4.