Inconsistent entry with iPad "magic keyboard" in text input fields

Using the iPad magic keyboard I cannot input text immediately into the demo text fields. If I focus away and click around a few times or take some other actions (pasting appear to be one) it will suddenly become live and I can enter text.

On reload sometimes the keyboard works, sometimes it doesn't.

Possibly related: using the "select all" hotkey (CMD-a) results in an extra cursor being visible (see screenshot)

Start with the demo text fields on an iPad using the Magic Keyboard, reproducing the intermittent inability to type after reload and the extra cursor after CMD-a. Compare behavior after focusing, clicking around, and pasting; done means text entry works immediately and select-all no longer shows an extra cursor.

Written by the indexing model from the issue text.