Here's how to reproduce.

1. Open a writer document
2. Start a numbered list, either with the button on the formatting bar or by pressing F12.
3. While still in the numbered list, on the horizontal ruler at the top, move the First Line Indent marker (the top triangle) to a half inch in (the amount you move it in doesn't really matter, just so long as there is some indent).  Leave the Hanging Indent marker (bottom triangle) in its default position.
4. Type some text so there is at least 2 lines of text.  Per the formatting done in step #3, you should see the first line of the numbered list item indented and the 2nd and following lines all aligned at the left side in the default position.
5. Highlight a word (any word) from any portion of the text in the numbered item  you typed in step #4 and press Ctrl-c to copy it to the clipboard.  
6. Use Ctrl-v to paste the copied word anywhere into the same numbered item or any subsequent numbered item in the same list.  When pasted, the pasting operation clears the formatting done above in step #3 and reverts the indention of that particular list item back to the default formatting.  This is the problem.
7. (As an aside, another smaller problem is that while pressing Ctrl-z to undo this operation does undo the pasting operation and reformats the list item back in the proper way, it leaves the entire paragraph in the list item highlighted, as opposed to just the section I was attempting to paste into, so often times after I undo the paste, I end up wiping the entire paragraph if I start typing again quickly, then I have to undo that as well.)

This copy-and-paste while preserving a list's formatting used to work right in the 3.x version.

Usually to work around this I do a "paste special" but that's kind of obnoxious for a 1-word copy and paste, because when pasting the paste special operation always prepends a number from the numbered list with the actual copied text, even if the copied selection is copied from the middle of the sentence in the numbered list, thus leaving me with a 2-word paste for a 1-word copied selection when I paste the copied selection, causing me to have to delete the prepended number.

I'm an attorney who uses AOO extensively and exclusively and I have to alter the formatting of numbered lists for every brief I write based on local court submission rules, so this is something that comes up every single day for me.