After upgrading to mac os 15.1 my Xcode has been complaining about iOS 18.1 that is missing. No matter what I do I cannot get it installed, I ended up clearing all caches, re-installing Xcode but that also failed. Downgrading to 16.0 or upgrading to 16.2 beta has the same issue.
Currently I cannot create any simulator or install any version of the iOS platform. Xcode would say it's installing but the runtime would not show up in the list. I have tried adding runtimes using xcrun simctl and also other methods indicated here.
Another colleague of mine that updated to OSX 15.1 also has the same issue so this doesn't seem like a isolated problem.
In the screenshots below you'll see 18.1 is installed but does not show up as an installed runtime.
