According to the documentation:The Info tab of your Xcode project contains a Document Types section for specifying the document types your app supports. At a minimum, you must specify a name for your document type and one or more UTIs that represent the data type. For example, to declare support for PNG files, you would include public.png as the UTI string. iOS uses the specified UTIs to determine if your app is eligible to open a given document.If you're using file-based URLs, then my concern would be that the UIActivityViewController is choosing a different UTI than what you specified as the correct UTI.Have you tried manually creating a UIActivityItemSource and specifying a custom UTI to rule out those issues?
Topic:
App & System Services
SubTopic:
Networking
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