Can't change zoom in iOS on javascript

I have website 1000x820 It's not a real website, don't ask me about responsive web design.

viewport:

<meta name="viewport" content="target-densitydpi=device-dpi, width=1000px, user-scalable=no">

Then on Iphone SE with iOS 10. Add to Home Screen.

Launch the application with 1000px width and it view very good with both orientation and we can change it. Of course we can't zoom. Focus an input and type text. While nothing zoom. Unfocus the input or change an orientation and our scale will be broken. We can't change it.

$('meta[name=viewport]').remove();
$('head').append('<meta name="viewport" content="target-densitydpi=device-dpi, width=1000px, user-scalable=no">' );

It didn't help me. Perversion with fonts too.

I've one bad idea. Trace changes of viewport and refresh the page.