Users submitting apps this week are seeing the following notification:
ITMS-90809: Deprecated API Usage - Apple will stop accepting submissions of apps that use UIWebView APIs . See https://developer.apple.com/documentation/uikit/uiwebview for more information.
This even occurs for SDK 8+ apps that use the WKWebView instead of the (deprecated) UIWebView. The reason is (I think) that there are still some UIWebView* left overs that aren't even used anymore. Removing them will very likely fix the issue.