As for the update just noticed this note for the software release post:
** NOTE: This update is only applicable to ROCK devices created using RoonOS 1.0 Build 254 or later (released after 11/09/2022). ROCK installations prior to this date will not receive this update. However, there’s no need for concern if you have an older ROCK installation, as the update is specifically designed for newer hardware capabilities introduced in Build 254. All Nucleus Titan device will get this update.
As far as the IP addresses, I think it may be related to how your network was hooked up? It may have just been “reset/renewed” and then got borked? Were there any updates to any devices or did your ISP update the hardware on their end? Who knows?
When you hit “connect” on the phone screen what happens?
Might try re-installing the app? if it can’t connect?
Can you use one of the PCs to run try roon remote to see if it will work from there?