Expected behavior
Close the keyboard by tapping the chat once or swiping down.
Like in Signal, Threema, Telegram and Whatsapp for example.
Actual behavior
The keyboard can only be closed by swiping down.
Explanation
Some prefer one method, some the other.
I think it would be good if users could choose between both methods.
In my opinion, tapping feels a bit faster and the chat history doesn’t slip.
Furthermore, it is handled the same way in iOS itself and in most apps.
For example Safari and Firefox. Partly also in Android.
So it’s a cross-app standard.
That’s why it can sometimes be annoying if you have to switch between apps frequently.
Especially for new users.
Conveniently, no UI change would be necessary.