Another oddity that seems like strange behaviour to me (but feel free to explain why it isn’t)
1 - Create a list of 5 items as a numbered list (so each item starts with 1. 2. 3. etc)
2 - Select the text from item 3 and cut it (Ctrl-X)
3 - Place the cursor at the start of the second item and press Ctrl-V to paste
The Numbering starts at 1 for the pasted item so the list now appears as: