Do you have a fancy custom loading animation instead of an UIActivityIndicatorView? You may want to check if it has an accessibility label so a VoiceOver user knows that something is happening. Something like "In progress" or "Loading" could work.
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With the button trait VoiceOver will read “button” after the accessibility label and will indicate the user that, when focused, they can double tap anywhere on the screen to interact with it. UIButton has this trait by default.
An interesting speech attribute for attributed accessibility labels is accessibilitySpeechIPANotation that lets you specify how VoiceOver should pronounce a label with the International Phonetic Alphabet (IPA) notation. https://developer.apple.com/documentation/foundation/nsattributedstring/key/accessibilityspeechipanotation

Configuring the header accessibility trait, when appropriate, is one of my favourite accessibility quick wins. In this example, you need a single swipe down, instead of 12 swipes to the right to get to from Podcasts to Artists, in the app.
Content © Daniel Devesa Derksen-Staats — Accessibility up to 11!