Describe the bug

Caret is erroneously positioned at the start of a RichText element when selecting a block in Firefox.

To Reproduce

Steps to reproduce the behavior:

1. Start with a post (I'm using a sizable post provided here).
2. Make sure no blocks are selected.
3. Click on the end of a textful RichText element, or click in the middle of the text.
4. Observed: Caret is positioned at the start of the element.

Expected behavior

Caret should be placed where I clicked.

Screenshots

Desktop (please complete the following information):

• OS: macOS
• Browser: Firefox Developer Edition