On Xbox (and possibly other platforms) when you paste any message you've previously sent in chat, you cannot edit the previously sent message after pasting it because the message deletes from the text box entirely as soon as you click on it and the caret pops up. This started immediately after 1.21.0.24 Preview that introduced the fix to MCPE-178574

To quickly reproduce this

1. Write any message and send it in chat
2. Attempt to paste that same message you just sent in chat
3. Press/click on the pasted message

Observed Results: The message deletes entirely from the text box as soon as you click on it rather than the caret popping up and allowing you to properly edit the message

Expected Results: The message should remain in the text box and allow you to edit it with the caret when you click on it