I've recently encountered this as well and was also confused about where it was coming from. I am aware that we do not use UIWebView, so after further investigation I found problem is with Xamarin.Forms.
You can find a Github conversation with different solutions here - https://github.com/xamarin/Xamarin.Forms/issues/7323.
If this answers your question, you can let me know by using the ticket's "Mark as resolved" button (in the email or ticket page). If you have any further questions about UI for Xamarin, feel free to open a new ticket so we can assist further.
Lance | Technical Support Engineer, Principal
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