If you have a problem with the Controller IP not changing on the CRE recording configuration, even though the extension has been moved to another controller. The CRE might have cached the extension's initial IP and it keeps using it.
We have seen this issue at Hosted sites, where there are many different controllers recorded through a few MBGs and the extension is re-purposed from one client on one controller to another client on another controller, but staying on the same MBG.
Restarting the CRE clears the cache and then the IP is picked up properly.