[Bug] Undo is ignored, when Copy-paste 2-3 paragraph from Wikipedia

When a user pastes text into the editor and uses the 'undo' function, then it should undo the paste.
Instead, the undo is ignored

Steps to reproduce:
1. Go to Wikipedia
2. Select and copy 2-3 paragraph
3. Paste in the editor.
4. Then the editor ignores the undo & redo.

Expected behavior:
The editor should undo the paste.