On iOS 14.5 & above, if your app uses deprecated UIWebView API, you may experience a known issue in which Appium’s connection to the app’s UIWebView leads to a crash. Please find more details here.
Solution
To ensure your app works fine on iOS 14.5 & above devices, we strongly recommend migrating your iOS app from deprecated UIWebview API to Apple's recommended WKWebview API. Please find more details here.