Thanks for reply, I had report a bug with the project that I modified, this is bug number: FB9538056.

When button create by old api: When I put figure on the button, then button text change color to black with some alpha. And when I leave figure from button, the button text color fade to black color. In this video, I tapped the last button which created by old api, it has the good transition when text color change. Then I tapped the first button which created by new api, it not has any transition. h t t p s:/ /vimeo.com/627271705

I saw this tutorial, you can find, in the this post video, the button change background and foreground color when button state changed. but in the system UIBarButtonItem, and UIButton created by UIButton(type: .system) has a subtle transition when foreground color changed. I think this is better than no any transition. The new button api broke that. But in the UIBackgroundConfiguration document: "When you apply a configuration to a view, UIKit performs the actual drawing and rendering of the background. When you use background configurations instead of rendering your own backgrounds, the system provides automatic view hierarchy management, support for interactive and interruptible animations and transitions, and performance optimizations." So, I hope this is a bug. No transition is so bad.

Hello, how long time from you reject by "other"?