If you're having trouble revealing phone numbers on the app, check out the iOS version you're using.
You'll need to upgrade if you're using iOS 14.0 or older, and then you should be able to view phone numbers again. Make sure 'private browsing' is turned off on iOS as well.
Keep in mind that if you're outside of Australia or using a proxy server, you won't be able to reveal phone numbers, post or edit ads, or message other posters.