Hey,
I have just tested this locally and I’m getting the same result. Technically speaking the moved post existed before the first post in the topic that it was moved in to, so I can see how it might be treated as an older post – appearing first in the list as new posts appear underneath.
However, I’m not entirely sure if this is how moved posts are supposed to behave, so will need a second opinion.
Have you tried using the ‘Reverse sort this topic’ option from the post admin toolbox inside the topic? This would put your new post at the top, but would also re-order the posts you’ve moved in, unless that isn’t a problem?
If there is a problem with the move post functionality we can open a ticket and investigate.. But as I said – would need a second opinion on whether there is actually a problem with it.