Created attachment 464555 [details] Xcode project illustrating the issue As of Safari 16.2 the text-decoration-thickness style no longer seem to affect the underlines of links that contain embedded <ruby> tags. This behavior seems new as of either Safari 16.1 or 16.2. Steps to Reproduce: I have attached an Xcode project that reproduces the issue in a simple iOS app. 1. Open the Xcode project and run it against an iOS 16.2 simulator. This will simply open the file index.html in a WKWebView. 2. Note that the first link (with an embedded ruby in it) appears offset by 20px and in red, showing that the text-underline-offset and text-decoration-color properties are being applied correctly. 3. Note that the first link has the default thickness, showing that the text-decoration-thickness property is not being applied correctly. 4. Note that the second link (without embedded ruby) appears with a thicker underline, showing that the text-decoration-thickness property is being applied. Now, rerun the Xcode project against an iOS 16.0 simulator. Note that the first link now matches the appearance of the second link, and the text-decoration-thickness property is applied correctly. Expected Result: I would expect the underline under the first link to appear as thick as the second link. Using Xcode Version 14.2 (14C18). Also reproducible in Safari on Mac: Version 16.2 (18614.3.7.1.5)