Why is the viewport setting lost?

Question

iOS

Hello, viewport setting:

<meta name="viewport" content="width=640, maximum-scale=1.0, user-scalable=no">

problem in Safari iOS 8-9 on iPhone: I
open the page,
turn off the network , refresh the
page - no connection,
turn on the network, update again and the page first starts loading with a width of 640, as if there is no maximum-scale setting, but there is initial-scale, and then either quickly zooms to a normal scale, or remains so.
either a refresh helps (and not always) or a switch to landscape-mode and back
, I understand that it sounds like a magical bug, but maybe someone has encountered a similar problem?

Answer 1

well, then set the initial-scale too.