I have a problem now connecting with Roon remote app on my iPhone X to a core on my computer. It worked fairly normally, but today it can’t find Roon core anymore. I tried reinstalling the app, rebooting, nothing helped. Had problem before with it, as sometimes only worked, if I turned on and off wi-fi connection.
My iPad app on the other hand works without any problems. Did upgrade.
Are you on the latest roon app for the iPhone? Downloaded from the APP store. The iOS apps don’t automatically update when the core is updated…some people have missed this in the past.