I have all the things clear and ready, but I can't create a simulator below iOS 26 and I can't figure out why.

I understand your questions, I meant running the app in a simulator by saying "building", sorry for not being clear. Xcode tries to build the app in iOS 26 because it doesn't recognize iOS 18.5 so it causes this error "No simulator runtime version from ["23A5287g"] available to use with iphone simulator SDK version 22F76" I have iOS 18.5 in Platform Support area and iOS 26 Beta 3 and my others as 17.5 and 16.5 in the Other Installed Platforms area in Xcode Settings > Components.