BUG : All elements keep focus on mobile

First of all you can check validity while you’re focused.
To that check the validity onInput (and for the richText use onKeyPress with a tiny timeout),

Second, I don’t understand how you expect it to lose focus if not by typing?
If you wish to lose focus by clicking the enter key, you should do:

$w('#input1, #input2, #richetext1').onKeyPress(event => {
if(event.key === 'Enter'){$w('#' + event.target.id).blur();} 
//Then run validity text
})