Text selection is reset after pressing a button in iOS/iPadOS

Problem
The Selection and Range article includes a demo button that should show an alert with the selected text. On desktop environments or non-Apple mobile devices, the demo works correctly. The alert shows the current selected text, while the selection itself is also maintained.

However on iOS/iPadOS devices(iPhone, iPad, ...) the text selection disappears as soon as you press the button and the alert appears with empty text.

I believe this is an issue with iOS/iPadOS Safari, rather than a bug in javascript.info but nevertheless I wonder if anyone could share some insight on why this isn't working as expected. I've tried my best but up to this point could not find any similar troubleshooting anywhere else.

https://user-images.githubusercontent.com/34783801/176479597-5d7d5621-a513-497a-a114-3cd4b2c055f8.MP4

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從 Selection and Range 文章及其示範按鈕開始，然後使用提供的範例在 iOS/iPadOS Safari 上重現該行為。將選取的文字和 alert 行為與桌面環境及非 Apple 行動環境進行比較；完成的標準是確定這是 Safari 的限制還是 demo 中的問題，並記錄證據或受支援的 workaround。