Oswald 200,300 rendering issue

Using multiple weights of Oswald (and for the most part, only Oswald, for text) on a WordPress site hosted on Pantheon. Linking in the font this way.

`@import url('https://fonts.googleapis.com/css?family=Oswald:200,300,400,500,600,700');`

For the most part it works, but the client has a user in SE Asia for whom there is an issue with any text using the 200 or 300 weights. The only characters that display are 'i', 'H', 'E' and some others (see attached, problem render on left and proper render on right).

I created a test page for the user, replacing all of the 200 and 300-weight text with 400. That test worked fine (and there was never any issue with heavier weights). The user can see all of the weights under Styles on the specimen page.

https://fonts.google.com/specimen/Oswald