Expected:
After adding any link, tapping “Undo” would undo the addition of the link.
Actual:
After adding a link which is set to “open in a new tap”, the Undo button does nothing and Redo button is greyed out.
Works in Paragraph, Header, List, Quote blocks.
To reproduce:
- Create a new post
- Add a paragraph block, type some text.
- Add a link and set it to “Open in a new tab”.
- Tap Undo and find it does nothing.
Video:

Tested on iPhone SE, (iOS 12.2) running WPiOS 12.7