I don't know how well mobile safari or the other skinned browsers masquerading as something different on iOS handle the WP backend but Android and Windows devices don't seem to have a problem it. Apps were once upon a time, a necessary and good thing. Now they're just another codebase that continues to accrue unnecessary technical debt.

It was a goid run but now the aging WP app should maybe just be discontinued in favor of crafting a great experience within the browser. With the modern web tech, there's little good reason to avoid developing one experience for all. Perhaps the WP app could even just suggest using an actual browser for the better experience to transition folks. Anything that iOS can't handle that's probably on Apple rather than WP or Gutenberg.