Hello, HOMH_809!
Does anyone experiencing face ID failure after IOS 18? mine started working intermittently yesterday around 10 am after I updated to 18.1. Device was working just fine before that, sometimes it works after a few taps in the camera (saw this "solution" in a reddit post and was surprised it worked) but I know for a fact is not a hardware issue since front camera is working just fine. Am using Iphone 13 pro max btw.
You said that you are on iOS 18.1. iOS 18.2 came out two days ago, so try updating and see if that fixes it.
You said that it’s not a hardware issue because the front camera works, but it still could be. Face ID includes a ton of sensors, including a LiDAR scanner, dot projector, flood illuminator, and a lot more.
If iOS 18.2 doesn’t fix the issue, first try working through the steps of this article: If Face ID isn't working on your iPhone or iPad Pro.
If the issue persists, you should go to Messages, then tap the New Message button (looks like a box with a pencil) in the top right corner, then click the plus (+) button next to the message field, then click Memoji, then try moving around your face and seeing if the Memoji responds.
I hope this helps!