Currently server join port is 2302, needs to be 3500 but it is using the correct Query port. I cannot find a way to change the Join port anywhere. I cannot add the server because the Query port is in use. Anyway to do this other than changing the query port of the 2302 to something and re-adding 3500? Prefer not to lose the stats.

There is no way to change the join port of a page. If you've changed the join port of a page, you'll need to re-add it.